Dissertations / Theses on the topic 'Green sustainable chemistry'

This thesis examines fundamental studies of catalysts for more sustainable processes, addressing three particular challenges: (1) Developing sulfur resistant catalysts that have potential applications in the processing of biomass for the production of liquid transportation fuels. (2) Reducing energy requirements and increasing the catalyst ease-of-use (especially water tolerance) for the hydrogenation of aromatics, particularly for the safe and feasible storage of hydrogen using the reversible toluene/methylcyclohexane couple. (3) Catalytically converting models of lignin building blocks as a source for renewable aromatic chemicals.

This thesis examines fundamental studies of catalysts for more sustainable processes, addressing three particular challenges: (1) Developing sulfur resistant catalysts that have potential applications in the processing of biomass for the production of liquid transportation fuels. (2) Reducing energy requirements and increasing the catalyst ease-of-use (especially water tolerance) for the hydrogenation of aromatics, particularly for the safe and feasible storage of hydrogen using the reversible toluene/methylcyclohexane couple. (3) Catalytically converting models of lignin building blocks as a source for renewable aromatic chemicals.

The implementation of sustainable solvents and processes is critical to new developments in reducing environmental impact, improving net efficiency, and securing economic profitability in the chemical and pharmaceutical industries. In order to address the challenge of sustainability, researchers have used switchable solvents for both reaction and separation by utilizing a built-in switch to undergo a step change in chemical and physical properties. This allows us to facilitate reactions in the solvent then activate the switch to enable separation and facile product recovery. Subsequently, we can recover the solvent for reuse and avoid energy- or waste-intensive separation processes; thus we are developing and using these switchable solvents as sustainable and environmentally benign alternatives to traditional processes. In this research, we enable the sustainable scale-up of a switchable solvent - piperylene sulfone - a "volatile" and recyclable DMSO replacement. In the development of this process, we improved the reaction performances and developed a green purification method. Furthermore, we enable and demonstrate the implementation of a Meerwein-Ponndorf-Verley (MPV) reduction, a pharmaceutically relevant reaction, into a continuous flow platform. The innovation of continuous flow processes can replace traditional batch reaction technology, and is indeed a key research area that has been acknowledged by the pharmaceutical industry. Additionally, we utilize the switchable sulfone solvents, piperylene and butadiene sulfone, for reaction and separation of HMF produced from monosaccharides as an alternative to a process which has been limited by an inefficient separation step.

Today the development of sustainable processes in the chemical industry is critical, and Green Chemistry represents an evolution from the conventional concepts of process efficiency. Twenty years ago, Paul Anastas and John Warner introduced this concept within the twelve principles. In this work, many aspects the twelve principles are applied, developing sustainable methods involving the use of metal catalysis and biocatalysis through one pot and cascade reactions.
In the first part of the PhD period, the use of the micellar catalysis was investigated, to perform reactions in water avoiding (or limiting) the use of the traditional organic solvents. The possibility to apply the micellar conditions for the hydrogen borrowing (HB) reaction to prepare amines was explored. Different Ru catalysts were screened using water as medium, under Microwave (MW) dielectric heating. Once optimized, the scope of the reaction was investigated using differently substituted amines and alcohols. Besides, the use of a biomass-derived solvent (GVL) was explored in Pd/C catalysed transformations to avoid the arching phenomena frequently observed using conventional solvents (e.g. toluene). A sustainable protocol for the synthesis of benzimidazoles employed different aliphatic and aromatic amines through a hydrogen transfer Pd/C. A heating profile and various studies of stability have been reported. A biocatalytic approach to pyridine and furans is also reported. These heterocycles are fundamental building blocks for the synthesis of pharmaceuticals, agrochemicals and organic material. Furthermore, these compounds are also employed in flavour and fragrance industry owing to their peculiar olfactory properties. Classical methodologies for their synthesis are based on low-yielding multistep methods, which involve the use of harsh conditions. Therefore, novel mild and greener methodologies for the preparation of heterocycles compounds are highly desirable. Aromatization of substituted 1,2,3,6-tetrahydropyridines (THPs) was performed using whole-cell monoamine oxidase MAO-N (variants from Aspergillus niger) catalyst. The aromatization of the tetrahydropyridine starting materials into the pyridine products was monitored through 1H NMR spectroscopy. During the optimization, different pyridine compounds are prepared to screen the best co-solvents and MAO-N variants. The kinetic profile of the biocatalytic transformation by MAO-N was also monitored via in situ 19F NMR experiments. Aromatization of different 2,5-dihydrofurans into corresponding furans was also performed using the Laccase/TEMPO catalytic system using mild conditions. A chemo- enzymatic cascade reaction starting directly from acyclic aliphatic precursor has been developed showing that metathesis Grubb's catalyst and the Laccase/TEMPO system can be used in combination for an efficient protocol.

The worldwide demand for energy-efficient and high-performing (opto)electronics, along with the increasing need for economically feasible and environmentally friendly chemistry, both require semiconducting materials that are both scalable and sustainable. The concern with waste generation and toxic/hazardous chemicals usage has already moulded many operations in chemical and manufacturing industries. To date, common syntheses to access organic semiconductors require the use of large quantities of toxic and/or flammable organic solvents, often involving reagents and by-products that are harmful to health and environment. Research in the field of organic electronics is now increasingly focusing on the development of new sustainable methodologies that allow to prepare active materials in a more efficiently way, caring further on safety and sustainability associated with production processes. The immediate approach applicable consist on the removal, or at least on the minimization, of harmful and toxic substances commonly employed within standard processes. The big elephant in the room in the synthesis of active materials is the amount of organic solvent employed, which could ideally be reduced by using aqueous solution of surfactants: in these nano/micro heterogeneous environments organic transformations can happen and often with unprecedent efficiency. Clearly, the process occur not through the dissolution of the reagents (starting materials and catalyst) but from their dispersion in water. Kwon as “micellar catalysis”, this strategy has proven to be highly effective on improving sustainability becoming a prominent topic in modern organic synthesis. In particular, the micellar catalysis strategy is compatible with the most common modern strategies employed for C-C and C-heteroatom bonds forming reactions and allow to perform reactions with high yields, in water and under very mild conditions. Nonetheless, the use of such method in the field of organic semiconductors is still limited, with only few relevant examples reported in literature concerning the preparation of π-conjugated molecular and polymeric materials. This Thesis describes the importance of introducing sustainability in the synthesis of organic semiconductors, satisfying several principles of the green chemistry guidance. Our research purpose is not to provide an exhaustive list of examples of such chemistry, but rather to identify a few key developments in the field that seem especially suited to large-scale synthesis. Then, the discussion will consider the synthetic approaches typically employed to access semiconducting materials with extended π-conjugated structures. In particular, the discussion will involve the well-known Pd-catalysed cross-coupling techniques. Finally, the topic of the work will focus on micro-heterogeneous environments as a new tool for introducing sustainability in the preparation of active materials in water, satisfying several criteria relevant to green chemistry. On my opinion, the micellar catalysis approach constitute today the more promising method to lower the overall cost and environmental impact in the production of organic semiconductors without affecting yields, purity, and device performance.
The worldwide demand for energy-efficient and high-performing (opto)electronics, along with the increasing need for economically feasible and environmentally friendly chemistry, both require semiconducting materials that are both scalable and sustainable. The concern with waste generation and toxic/hazardous chemicals usage has already moulded many operations in chemical and manufacturing industries. To date, common syntheses to access organic semiconductors require the use of large quantities of toxic and/or flammable organic solvents, often involving reagents and by-products that are harmful to health and environment. Research in the field of organic electronics is now increasingly focusing on the development of new sustainable methodologies that allow to prepare active materials in a more efficiently way, caring further on safety and sustainability associated with production processes. The immediate approach applicable consist on the removal, or at least on the minimization, of harmful and toxic substances commonly employed within standard processes. The big elephant in the room in the synthesis of active materials is the amount of organic solvent employed, which could ideally be reduced by using aqueous solution of surfactants: in these nano/micro heterogeneous environments organic transformations can happen and often with unprecedent efficiency. Clearly, the process occur not through the dissolution of the reagents (starting materials and catalyst) but from their dispersion in water. Kwon as “micellar catalysis”, this strategy has proven to be highly effective on improving sustainability becoming a prominent topic in modern organic synthesis. In particular, the micellar catalysis strategy is compatible with the most common modern strategies employed for C-C and C-heteroatom bonds forming reactions and allow to perform reactions with high yields, in water and under very mild conditions. Nonetheless, the use of such method in the field of organic semiconductors is still limited, with only few relevant examples reported in literature concerning the preparation of π-conjugated molecular and polymeric materials. This Thesis describes the importance of introducing sustainability in the synthesis of organic semiconductors, satisfying several principles of the green chemistry guidance. Our research purpose is not to provide an exhaustive list of examples of such chemistry, but rather to identify a few key developments in the field that seem especially suited to large-scale synthesis. Then, the discussion will consider the synthetic approaches typically employed to access semiconducting materials with extended π-conjugated structures. In particular, the discussion will involve the well-known Pd-catalysed cross-coupling techniques. Finally, the topic of the work will focus on micro-heterogeneous environments as a new tool for introducing sustainability in the preparation of active materials in water, satisfying several criteria relevant to green chemistry. On my opinion, the micellar catalysis approach constitute today the more promising method to lower the overall cost and environmental impact in the production of organic semiconductors without affecting yields, purity, and device performance.

Acrylic monomers are important materials that represent a large portion of the economy. The current industrial synthesis hydrates cyanohydrins with sulfuric acid, a process which results in large amounts of waste and significant energy costs. A transition metal catalyzed, acid free hydration of cyanohydrins would be beneficial from both economic and environmental standpoints. However, this reaction is challenging, as many catalysts are poisoned by the cyanide released when cyanohydrins degrade. Therefore the development of a catalyst that is resistant to cyanide poisoning is the ideal method to circumvent these difficulties. This dissertation describes several cyanohydrin hydration catalysts, with an emphasis on nanoparticle catalysts. These are at the interface between the homogeneous and heterogeneous catalysts that have been explored previously for this reaction. Chapter I surveys previous studies on nanoparticle catalysts for nitrile hydration and their implications for the hydration of cyanohydrins. Chapter II reports on the homogeneous platinum catalysts [PtHCl(P(NMe2)3)2] and [PtH2(P(NMe2)3)2], exploring secondary coordination sphere effects to enhance nitrile hydration. Chapter III describes another example of this type of complex, [PtH2(P(OMe)3)2], that forms catalytically active nanoparticles under reaction conditions. Explorations of the reactivity of this catalyst with nitriles and cyanohydrins are also described in this chapter. Chapter IV investigates a silver nanoparticle catalyst with a water soluble phosphine (1,3,5-triaza-7-phosphaadamantane) ligand for its activity towards the hydration of nitriles and cyanohydrins. The results of the degradation of the nanoparticles in the presence of cyanide are also described. Chapter V reports on the preparation and examination of a solid supported nickel catalyst for cyanohydrin hydration. Finally, Chapter VI describes how these investigations have made progress towards the development of a cyanide resistant nitrile hydration catalyst. This dissertation includes previously published and unpublished co-authored material.
2015-09-29

Metal organic frameworks (MOFs) is a quite recently discovered porous material group which shows potential in many different areas. One of these areas is carbon capture; the framework structure of the porous materials allows gas molecules to adsorb to the surface of the pores. MOFs are conventionally synthesised at high temperatures and with hazardous solvents. The goal of this projectwas to synthesise highly porous MOFs at room temperature with water as the main solvent, using environmentally friendly and non-hazardous precursors. As well as the room temperature synthesis, conventional synthesis methods were used with the same precursors as comparison. The materials were characterised with X-ray diffraction, thermogravimetrical methods and IR-spectroscopy. To assess the porosity of the materials, gas adsorption evaluation was performed with CO2, N2, SF6, and CH4 at 20⁰C. In the end, three novel porous magnesium-based materials and one zirconium-based material were successfully synthesised. One of the magnesium-based materials showed a moderately high CO2 adsorption (2.38mmol/g), and could be synthesised at room temperature. The zirconium-based material showed a remarkably high selectivity (17.7) for SF6 over N2 and a high surface area (550m2/g)

The need to reduce humankind reliance on fossil fuels by exploiting sustainably the planet renewable resources is a major driving force determining the focus of modern material research. For this reason great interest is nowadays focused on finding alternatives to fossil fuels derived products/materials. For the short term the most promising substitute is undoubtedly biomass, since it is the only renewable and sustainable alternative to fossil fuels as carbon source. As a consequence efforts, aimed at finding new synthetic approaches to convert biomass and its derivatives into carbon-based materials, are constantly increasing. In this regard, hydrothermal carbonisation (HTC) has shown to be an effective means of conversion of biomass-derived precursors into functional carbon materials. However the attempts to convert raw biomass, in particular lignocellulosic one, directly into such products have certainly been rarer. Unlocking the direct use of these raw materials as carbon precursors would definitely be beneficial in terms of HTC sustainability. For this reason, in this thesis the HTC of carbohydrate and protein-rich biomass was systematically investigated, in order to obtain more insights on the potentials of this thermochemical processing technique in relation to the production of functional carbon materials from crude biomass. First a detailed investigation on the HTC conversion mechanism of lignocellulosic biomass and its single components (i.e. cellulose, lignin) was developed based on a comparison with glucose HTC, which was adopted as a reference model. In the glucose case it was demonstrated that varying the HTC temperature allowed tuning the chemical structure of the synthesised carbon materials from a highly cross-linked furan-based structure (T = 180oC) to a carbon framework composed of polyaromatic arene-like domains. When cellulose or lignocellulosic biomass was used as carbon precursor, the furan rich structure could not be isolated at any of the investigated processing conditions. These evidences were indicative of a different HTC conversion mechanism for cellulose, involving reactions that are commonly observed during pyrolytic processes. The evolution of glucose-derived HTC carbon chemical structure upon pyrolysis was also investigated. These studies revealed that upon heat treatment (Investigated temperatures 350 – 900 oC) the furan-based structure was progressively converted into highly curved aromatic pre-graphenic domains. This thermal degradation process was observed to produce an increasingly more hydrophobic surface and considerable microporosity within the HTC carbon structure. In order to introduce porosity in the HTC carbons derived from lignocellulosic biomass, KOH chemical activation was investigated as an HTC post-synthesis functionalisation step. These studies demonstrated that HTC carbons are excellent precursors for the production of highly microporous activated carbons (ACs) and that the porosity development upon KOH chemical activation is dependent on the chemical structure of the HTC carbon, tuned by employing different HTC temperatures. Preliminary testing of the ACs for CO2 capture or high pressure CH4 storage yielded very promising results, since the measured uptakes of both adsorbates (i.e. CO2 and CH4) were comparable to top-performing and commercially available adsorbents, usually employed for these end-applications. The combined use of HTC and KOH chemical activation was also employed to produce highly microporous N-doped ACs from microalgae. The hydrothermal treatment of the microalgae substrate was observed to cause the depletion of the protein and carbohydrate fractions and the near complete loss (i.e. 90%) of the microalgae N-content, as liquid hydrolysis/degradation products. The obtained carbonaceous product showed a predominantly aliphatic character indicating the presence of alkyl chains presumably derived from the lipid fractions. Addition of glucose to the initial reaction mixture was found out to be extremely beneficial, because it allowed the fixation of a higher N amount, in the algae derived HTC carbons (i.e.  60%), and the attainment of higher product yields (50%). Both positive effects were attributed to Maillard type cascade reactions taking place between the monosaccharides and the microalgae derived liquid hydrolysis/degradation products, which were in this way recovered from the liquid phase. KOH chemical activation of the microalgae/glucose mixture derived HTC carbons produced highly microporous N-doped carbons. Although the activation process led to a major reduction of the N-content, the retained N-amount in the ACs was still considerable. These features render these materials ideal candidates for supercapacitors electrodes, since they provide extremely high surface areas, for the formation of electric double-layer, coupled to abundant heteroatom doping (i.e. N and O) necessary to obtain a pseudocapacitance contribution.
Die Notwendigkeit, die Abhängigkeit der Menschheit von fossilen Brennstoffen zu reduzieren ist die treibende Kraft hinter aktuellen Forschungsanstrengungen in den Materialwissenschaften. Folglich besteht heutzutage ein erhebliches Interesse daran Alternativen zu Materialien, die aus fossilen Resourcen gewonnen werden, zu finden. Kurzfristig ist zweifellos Biomasse die vielversprechendste Alternative, da sie aus heutiger Sicht die einzige nicht-fossile, nachhaltige und nachwachsende Kohlenstoffquelle ist. Konsequenterweise werden die Antrengungen neue Syntheseansätze zur Konvertierung von Biomasse und ihren Derivaten in kohlenstoffbasierten Materialien forwährend erhöht. In diesem Zusammenhang hat sich die Hydrothermalkarbonisierung (HTC) als sehr vielseitiges Werkzeug zur Konvertierung von Biomasse-basierten Ausgangsstoffen in funktionale Kohlenstoffmaterialien herausgestellt. Dennoch gibt es bisher wenige Ansätze um rohe Biomasse, genauer gesagt Lignicellulose, direkt in funktionale Materialien umzusetzen. Könnte der direkte Einsatz von roher Biomasse Verfahren wie der HTC zugänglich gemacht werden, würde dies die Nachhaltigkeit des Verfahrens immens steigern. Daher wurde in dieser Dissertation die Hydrothermalkarbonisierung von kohlenhydratreicher (d. h. Lignicelluse) und proteinreicher (d. h. Microalgae) Biomasse systematisch analysiert. Diese Untersuchung galt dem Ziel einen besseren Einblick in das Potential dieser thermochemischen Verarbeitungsmethode funktionale Kohlenstoffmaterialien aus unverarbeiteter Biomasse hervorzubringen zu gewinnen. Die hergestellten Materialien wurden mittels chemischer Aktivierung nachträglich weiter behandelt. Dieser zusätzliche Verarbeitungsschritt ermöglichte die Herstellung hochporöser aktiverter Kohlenstoffe (AC). Die aus Lignicellulose gewonnenen ACs zeigten exzellente Eigenschaften bei der Aufnahme von CO2 und der Hochdruckspeicherung von CH4 währen die aus Microalgae gewonnen Eigenschaften an den Tag legten (z. B. hohe Oberfläche und N-Dotierung), welche sie zu vielversprechenden Materialien für Superkondensatoren machen. Die in dieser Dissertation präsentierte Arbeit zeigte außergewöhnliche Fortschritte in Richtung der Anwendung von unbehandelter Biomasse als Ausgangsmaterial für die Produktion von funktionalen Kohlenstoffen.

The challenge for the future was defined by the Brundtland Commission (1987) and by the Rio Declaration (1992), in which the fundamental principles for achieving a sustainable development were provided. Sustainable chemistry can be defined as the contribution of chemistry to the implementation of the Rio Declaration. This thesis shows how Pressurized Fluid Extraction (PFE) can be utilized in chemical analysis, and how this correlates to Green Chemistry.

The reliability and efficiency of the PFE technique was investigated for a variety of analytes and matrices. Applications discussed include: the extraction of the antioxidant Irganox 1076 from linear low density polyethylene, mobile forms of phosphorus in lake sediment, chlorinated paraffins from source-separated household waste, general analytical method for pesticide residues in rape seed, total lipid content in cod muscle, and squalene in olive biomass. Improved or comparable extraction yields were achieved with reduced time and solvent consumption. The decrease in use of organic solvents was 50-90%, resulting in minimal volatile organic compounds emissions and less health-work problem. Due to higher extraction temperatures and more efficient extractions, the selection of solvent is not as important as at lower temperatures, which makes it possible to choose less costly, more environmentally and health beneficial solvents. In general, extraction times are reduced to minutes compared to several hours. As a result of the very short extraction times, the amount of co-extracted material is relatively low, resulting in fewer clean-up step and much shorter analysis time. Selective extractions could be obtained by varying the solvent or solvent mixture and/or using adsorbents.

In this thesis, the PFE technique was compared to the twelve principles of Green Chemistry, and it was shown that it follows several of the principles, thus giving a major contribution to sustainable chemistry.

The present PhD thesis entitled Sustainable processes for the chemical upgrading of renewables has dealt with the design and implementation of both batch and continuous-flow methods for: i) the upgrading of biobased substrates including glycerol and its derivatives and 5-hydroxymethylfurfural (HMF); ii) the synthesis of cyclic organic carbonates via catalytic insertion of CO2 into terminal epoxides; iii) the preparation of polyesters from Kraft lignin (KL) with poly-anhydrides and polyisopropenyl esters as crosslinking agents. The first and part of the second year have been dedicated to the study of the reactivity of enol esters, particularly the nontoxic isopropenyl acetate (iPAc), with renawable 1,2-diols, glycerol and some of its derivatives. The design of original catalytic tandem protocols was developed, by which the above-mentioned reactants were converted into the corresponding acetates and acetal products with even 100% carbon efficiency. Based on these results, three papers were published on international peer-reviewed journals. Then, a period abroad at the University of Sydney under the supervision of Prof. T. Maschmeyer to start a cotutelle program for the achievement of the joint Italian-Australian PhD title was planned. However, due to the pandemic, the mobility was forbidden, and the related experimental work has been converted in a remote collaboration finalized at the writing of a review paper on the synthesis and reactivity of enol esters. Periodic videocalls have been organized with Prof. Maschmeyer during which the progress of the review article has been discussed. The resulting review paper entitled “Isopropenyl esters in green organic synthesis” and authored by D. Rigo, G. Fiorani, A. Masters, T. Maschmeyer, and M. Selva is currently almost finished, and its submission is expected by the end of this year. Parallelly, two new experimental studies were undertaken aimed to: a) the design of a protocol for the activation of CO2 in the insertion on terminal epoxides in the presence of a binary homogenous mixture of diethylene glycol and NaBr as catalyst/solvent; a) the upgrading of HMF through diversified approaches of transesterification, transcarbonation, reductive amination, aldol condensation, and vinylation reactions using safe reagents and solvents as iPAc, dimethyl carbonate, water, and ad-hoc prepared ionic liquids. Based on these results, two papers were published on international peer-reviewed journals. From March to September 2021 (6.5 months) an exchange research period at Stockholm University under the supervision of Prof. Joseph Samec has been undertaken. The activity was focused on the synthesis of lignin-based thermosetting polyesters. A scalable, ecofriendly, and solvent-free protocol for the preparation of the desired materials using a mixture of polyanhydrides and poly-isopropenyl esters as crosslinking agents of Kraft lignin (KL) has been implemented. Based on these results, a paper entitled “A new family of thermosets: Kraft lignin polyadipates” authored by D. Di Francesco, D. Rigo, K. R. Baddigam, A. Mathew, N. Hedin, M. Selva, J. S. M. Samec has been submitted to an international peer-reviewed journal and is currently on peer reviewing. In addition, the following book chapter M. Selva, G. Fiorani, D. Rigo “Supercritical Solvents” In Sustainable Organic Synthesis: Tools and Strategies, Chapter 10; A. Palmieri, S. Protti, Eds. RSC book, 2021 has been published.
The present PhD thesis entitled Sustainable processes for the chemical upgrading of renewables has dealt with the design and implementation of both batch and continuous-flow methods for: i) the upgrading of biobased substrates including glycerol and its derivatives and 5-hydroxymethylfurfural (HMF); ii) the synthesis of cyclic organic carbonates via catalytic insertion of CO2 into terminal epoxides; iii) the preparation of polyesters from Kraft lignin (KL) with poly-anhydrides and polyisopropenyl esters as crosslinking agents. The first and part of the second year have been dedicated to the study of the reactivity of enol esters, particularly the nontoxic isopropenyl acetate (iPAc), with renawable 1,2-diols, glycerol and some of its derivatives. The design of original catalytic tandem protocols was developed, by which the above-mentioned reactants were converted into the corresponding acetates and acetal products with even 100% carbon efficiency. Based on these results, three papers were published on international peer-reviewed journals. Then, a period abroad at the University of Sydney under the supervision of Prof. T. Maschmeyer to start a cotutelle program for the achievement of the joint Italian-Australian PhD title was planned. However, due to the pandemic, the mobility was forbidden, and the related experimental work has been converted in a remote collaboration finalized at the writing of a review paper on the synthesis and reactivity of enol esters. Periodic videocalls have been organized with Prof. Maschmeyer during which the progress of the review article has been discussed. The resulting review paper entitled “Isopropenyl esters in green organic synthesis” and authored by D. Rigo, G. Fiorani, A. Masters, T. Maschmeyer, and M. Selva is currently almost finished, and its submission is expected by the end of this year. Parallelly, two new experimental studies were undertaken aimed to: a) the design of a protocol for the activation of CO2 in the insertion on terminal epoxides in the presence of a binary homogenous mixture of diethylene glycol and NaBr as catalyst/solvent; a) the upgrading of HMF through diversified approaches of transesterification, transcarbonation, reductive amination, aldol condensation, and vinylation reactions using safe reagents and solvents as iPAc, dimethyl carbonate, water, and ad-hoc prepared ionic liquids. Based on these results, two papers were published on international peer-reviewed journals. From March to September 2021 (6.5 months) an exchange research period at Stockholm University under the supervision of Prof. Joseph Samec has been undertaken. The activity was focused on the synthesis of lignin-based thermosetting polyesters. A scalable, ecofriendly, and solvent-free protocol for the preparation of the desired materials using a mixture of polyanhydrides and poly-isopropenyl esters as crosslinking agents of Kraft lignin (KL) has been implemented. Based on these results, a paper entitled “A new family of thermosets: Kraft lignin polyadipates” authored by D. Di Francesco, D. Rigo, K. R. Baddigam, A. Mathew, N. Hedin, M. Selva, J. S. M. Samec has been submitted to an international peer-reviewed journal and is currently on peer reviewing. In addition, the following book chapter M. Selva, G. Fiorani, D. Rigo “Supercritical Solvents” In Sustainable Organic Synthesis: Tools and Strategies, Chapter 10; A. Palmieri, S. Protti, Eds. RSC book, 2021 has been published.

Thesis (Ph. D.)--Chemical Engineering, Georgia Institute of Technology, 2009.
Committee Co-Chair: Eckert, Charles; Committee Co-Chair: Liotta, Charles; Committee Member: Bommarius, Andreas; Committee Member: Fernández, Facundo; Committee Member: Lu, Hang. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The research  concerning lignin in high value applications has increased  during the last years due to its renewability and availability in the black liquor from pulp mills. Today  the major part of kraft lignin found  in the black liquor is used as fuel to gain energy  in the recovery boiler. Lignin functions as natural  glue in plants so that the function of kraft lignin as a phenol replacement in wood adhesives has been researched. Due to lignin's low reactivity the molecule must be modified  prior to use. Demethylation is a method  to increase the phenolic content  in lignin to produce  more reactive  sites. Thiol  mediated  and iodine mediated demethylation was performed. Demethylated lignin was characterized by changes  in phenolic and hydroxylic groups,  molecular  mass, elemental  composition and other  properties  using methods including  UV, SEC and 31 P NMR.   The results showed  a decrease in the phenolic  content  contrary  to the increase  that was expected. Really low yields were also gained  which makes the results non-representative. Size evaluation showed  that the percentage of high molecular  content  in the demethylated lignin sample  had increased,  which  point towards the loss of low molecular mass fractions.  Due to demethylation lignin may have been more hydrophilic and soluble  in DMF and water. In addition  to this bond cleavage  may have produced  smaller  fragments which also increase  the solubility. The results point towards  the loss of smaller  fragments in the DMF and water phases.   The applied demethylation methods were evaluated  in context of green chemistry. Production, waste,  involving chemicals and efficiency were discussed  and analyzed. The applied demethylation methods  use DMF as solvent  which  is not a green alternative, greener solvents such as water or other energy  adding  methods  could  be used to make the process  greener.  The use ofNaOMe produces  methanol  as a byproduct  which could be eliminated by using NaOH, future studies  on the efficiency of the bases in the needs to be done.   Nature science  has a reputation  of being hard and firm. By bringing  in social  issues in science education new ways of looking  at science  opens  up. A social problem  and at the same time an environmental problem  in today's  society  is the large plastic mountain in the Pacific Ocean. An educational material  of the "Samhallsfragor med Naturvetenskapligt Innehiill",SNI, (Societal  issues with scientific content)  principle  has been evaluated with respect  to the abilities that can developed together  with whether  students  increase  their science  knowledge through  this. The study showed  that students  can develop  almost  all abilities  described  in the curriculum and their knowledge in science  by this type of material. Keywords Biomaterial, lignin reactivity,  thiol mediated  demethylation, iodine mediated demethylation, green chemistry, SNl-fall.
Forskning kring lignin i produkter har ökat under de senaste åren på grund av lignins fornyelsebarhet och tillganglighet i svartluten från massabruken. Idag används den största delen av sulfatligninet från svartluten som bränsle for att producera energi i sodapannan. Lignin fungerar som ett naturligt lim i växter och på grund av detta undersöks funktionen av kraftlignin som fenolersättning i trälim. Med anledning av ligninmolekylens låga reaktivitet behover lignin modifieras fore användning i produkter. Demetylering är en metod för att öka fenolhalten i lignin och skapa en högre reaktivitet. I denna studie utfördes Tiolmedierad och jodidmedierad demetylering. Det demetylerade ligninet utvärderades med avseende på forändringar i  fenol-och hydroxylgrupper, molekylvikt, elementarsammansättning och andra egenskaper med hjälp av olika metoder,inklusive UV, SEC och 31 P NMR.   Resultaten visade en minskning i fenolinnehall  i motsats till den ökning som förväntades. Riktigt låga utbyten påvisades också vilket gör att resultaten inte är representativa. Storleksutvärdering  visade att andelen med högt molekylviktsinnehåll i det demetylerade ligninproven hade ökat, vilket pekar mot förlust av lågmolekylära fraktioner. På grund av demetyleringen kan ligninet ha blivit mer hydrofilt och lösligt i DMF och vatten. Utöver detta kan bindningsklyvning ha skapat mindre fragment som också ökat lösligheten. Resultaten pekar mot förlust av mindre fragment i DMF-och vattenfaserna.   De tillämpade demetyleringsmetoderna  utvärderades med avseende på grön kemi. Produktion, avfall, kemikalier och effektivitet diskuterades och analyserades. De tillämpade demetyleringsmetoderna  använder DMF som lösningsmedel, vilket inte är ett grönt alternativ. Grönare lösningsmedel såsom vatten, eller andra typer av energitillsättning, kan användas för att göra processen miljövänligare. Användandet av NaOMe i den thiolmedierade demethyleringen skapar metanol som en biprodukt vilket kan bytas ut mot vatten om NaOH istället används. Vidare studier behöver göras för att undersöka de båda baserna effektivitet.   Naturvetenskapen har ett rykte om att vara hård och fast. Genom att föra in sociala frågor i den naturvetenskapliga utbildningen kan nya sätt att se på vetenskapen skapas. Ett samhälls problem och samtidigt ett miljöproblem i dagens sämhalle är det stora plast berget i Stillahavet. Ett undervisningsmaterial för"Samhällsfrågor Med Naturvetenskapligt Innehåll", SNI, principen har utvärderats med avseende på vilka förmågor som kan tränas tillsammans med huruvida eleverna kan öka sin vetenskapliga kunskap. Studien visade att eleverna kan utveckla nästan alia formågor som beskrivs i läroplanen och sina kunskaper inom naturvetenskapen genom denna typ av utbildningsmaterial.   Nyckelord Biomaterial, ligninreaktivitet, tiol medierad demetylering, jodmedierad demetylering,grön kemi, SNI-fall.

Thesis (Ph.D.)--Chemical Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Charles A. Eckert; Committee Co-Chair: Charles L. Liotta; Committee Member: Christopher W. Jones; Committee Member: Facundo M. Fernandez; Committee Member: Thomas F. Fuller.

Vinyltrialkoxysilanes are grafted onto polyolefins via a radical mechanism; in a subsequent step, the pendant alkoxysilanes hydrolyze and condense upon exposure to water, resulting formation of crosslinks. Straight chain hydrocarbons were used as model compounds to investigate the regioselectivity of vinyltrimethoxysilane grafting. To stabilize the water-sensitive grafted products, the methoxy groups were substituted using phenyllithium. It was found that this reaction must be carried out for a minimum of three days to ensure full substitution. The grafted products were then separated on a weight basis using semi-preparative HPLC. Analysis of the di-grafted fraction using edited HSQC and HSQC-TOCSY NMR showed that radical propagation occurs via 1,4- and 1,5-intramolecular hydrogen shifts along the hydrocarbon backbone, resulting in multiple grafts per backbone. Post-combustion carbon capture targets CO₂ emissions from large point sources for capture and sequestration. A new class of potential carbon capture agents known as reversible ionic liquids (RevILs) has been synthesized and evaluated in terms of potential performance parameters (e.g. CO₂ capacity, viscosity, enthalpy of regeneration). These RevILs are silylated amines, which react with CO₂ to form a salt comprising an ammonium cation and a carbamate anion that is liquid at room temperature. Structural modifications of the basic silylamine skeleton result in drastic differences in the performance of the resulting RevIL. Systematic variation of the silylated amines allowed determination of a structure-property relationship, and continued iterations will allow development of an ideal candidate for scale-up. The properties and potential applications of gold nanoparticles (AuNP) are highly dependent on their size and shape. These properties are commonly controlled during liquid-phase synthesis through the use of capping agents, which must be removed following synthesis. Reverse micelles can also be used to control the morphology of AuNP during their synthesis. When RevILs are used in the formation of these reverse micelles, either as the disperse phase or as the surfactant, the built-in switch can be used to release the nanoparticles following their synthesis. This release on command could decrease the post-synthetic steps required to clean and purify AuNP prior to use. We have successfully synthesized AuNP using a number of different RevILs.

Stormwater runoff is one of the main sources of pollution for urban waterways. Stormwater has traditionally been managed through concrete-based storm drainage systems, but the past twenty years have introduced an alternative in the form of green infrastructure. Green infrastructure for stormwater management involves the use of low impact development (LID), often vegetated facilities to mimic natural hydrologic systems that capture and allow infiltration of rainwater where it falls and from impervious surfaces upstream, before entering the drainage system. Portland, Oregon and Los Angeles, California have adopted green infrastructure into their stormwater management plans. For this project, bioswales, a form of vegetated LID facility, were tested in each city to determine their pollutant retention capabilities. Results from Portland show that bioswales filter out heavy metals effectively, and results from Los Angeles show that bioswales accumulate heavy metals in the soil over the course of the year (also due to filtering out metals from the stormwater). These results raise the question of whether accumulation can reach dangerous levels or saturate the soil with pollutants so that removal efficiency is diminished, indicating a need for further monitoring. However, the success of bioswales up to this point is encouraging and indicates that this method should continue to be employed.

Succinic acid is a compound used for manufacturing lacquers, resins, and other coating chemicals. It is also used in the food and beverage industry as a flavor additive. It is predominantly manufactured from petrochemicals, but it can also be produced more sustainably by fermentation of sugars from renewable feedstocks (biomass). Bio-based succinic acid has excellent potential for becoming a platform chemical (building block) for commodity and high-value chemicals. In this study, we focused on the production of bio-based succinic acid from the fiber of sweet sorghum (SS), which has a high fermentable sugar content and can be cultivated in a variety of climates and locations around the world. To avoid competition with food feedstocks, we targeted the non-edible ‘bagasse’, which is the fiber part after extracting the juice. Initially, we studied various conditions of pretreating SS bagasse to remove most of the non-fermentable portions and expose the cellulose fibers containing the fermentable sugars (glucose). Concentrated (83%) phosphoric acid was utilized at mild temperatures of 50-80 °C for 30-60 minutes at various bagasse loadings (10-15%) using a partial factorial experimental design. After pretreatment, the biomass was subjected to enzymatic hydrolysis with commercial cellulase enzyme (Cellic® Ctec2) to identify the pretreatment conditions that lead to the highest glucose yield that is critical for the production of succinic acid via fermentation with the bacterium Actinobacillus succinogenes. As the pretreatment temperature and duration increased, the bagasse color changed from light brown to dark brown-black, indicating decomposition, which ranged from 15% to 72%. The pretreatment results were fitted with an empirical model that identified 50 °C for 43 min at 13% solids loading as optimal pretreatment conditions that lead to the highest glucose release from sweet sorghum bagasse. Biomass pretreated at those conditions and subjected to separate enzymatic hydrolysis and fermentation with A. succinogenes yielded almost 18 g/L succinic acid, which represented 90% of the theoretical yield, a very promising performance that warranties further investigation of bio-based succinic acid production from sweet sorghum bagasse, as a more sustainable alternative to succinic acid produced from fossil sources, such as oil.

Les alginates sont des polysaccharides naturels extraits des macro-algues brunes, et disponibles en quantités quasi-illimitées à bas prix. En présence de cations divalents ou par diminution de pH, ces polymères renouvelables ont la capacité de former instantanément des hydrogels, que l’on peut ensuite transformer en solvogels et aérogels, caractérisés par de grandes surfaces spécifiques, de bonnes propriétés mécaniques, une bonne résistance à une large gamme de solvants organiques et une manipulation aisée. Ces dernières années, les gels d’alginate ont été utilisés comme supports d’espèces chimiques actives en catalyse hétérogène, ainsi que comme catalyseurs acides de Brønsted. Dans ce contexte, le présent travail contribue à élargir l’utilisation des gels d’alginate à la catalyse hétérogène asymétrique, en exploitant les propriétés particulières de ces biomatériaux. Dans la première partie de cette étude, les billes de gel d’acide alginique ont été utilisées comme support pour préparer une version hétérogène d’un catalyseur chiral homogène, dérivé de la quinine, pour l’addition de Michael asymétrique. Contrairement aux approches classiques d’immobilisation de catalyseurs par liaison covalente, notre approche consiste à immobiliser l’organocatalyseur par simples interactions non-covalentes. Les résultats présentés ici montrent que l’adsorption du catalyseur, une base de Lewis organique, se produit avec d’excellents rendements sur les gels d’acide alginique en utilisant un protocole très simple et tout à fait reproductible. Les billes d’organocatalyseur chiral supporté sont actives comme catalyseurs hétérogènes dans l’addition de Michael d’aldéhydes sur les nitroalcènes, permettant l’obtention du produit attendu avec de bons rendements et de bonnes diastéréosélectivités et énantiosélectivités. Dans cette réaction, les fonctions acides carboxyliques du biopolymère agissent à la fois comme co-catalyseur acide et comme site d'ancrage non covalent pour le catalyseur amine tertiaire. L’utilisation de gels hétérocationiques, formés par l’échange partiel de protons par des cation alcalino-terreux, ont permis pour cette réaction d’obtenir des catalyseurs avec une meilleure tenue mécanique, une plus grande porosité, menant ainsi à de plus grandes activités catalytiques. Dans un second temps, les gels d’alginate ont aussi été utilisés comme un moyen possible de transférer la chiralité du support alginate à un produit de réaction sans l’aide d’un inducteur chiral. La réaction de Friedel-Crafts des nitroalcènes avec les indoles a été choisie comme réaction modèle pour évaluer l’énantio-induction éventuelle de métaux de Lewis supportés sur gels d’alginate. La librairie de catalyseurs testée est active dans la réaction. Les catalyseurs comprenant du cuivre et du Baryum ont montré une bonne activité et surtout ont permis de prouver l’effet inducteur chiral du support, puisqu’un excès énantiomérique modéré est obtenu. De plus, ces deux métaux donnent chacun accès majoritairement aux deux énantiomères possibles, ce qui est un résultat important puisque l’alginate ne présente qu’un seule forme énantiomérique. Le choix du métal pourrait donc orienter l’obtention de l’un ou l’autre des énantiomères. La nature hétérogène de ces catalyseurs est prouvée en utilisant les gels au Cu, et la recyclabilité du système est également montrée puisqu’une perte très faible d’activité et une conservation de la stéréosélectivité sont observées sur cinq cycles réactionnels. Ce travail représente la première utilisation des gels d’alginate comme supports de catalyseurs pour l’organocatalyse chirale, et le premier exemple d’induction chirale par le support alginate uniquement pour une réaction de couplage C-C d’intérêt pour la chimie fine
Alginates are natural polysaccharides extracted from brown macro-algae, available in nearly unlimited amounts at very low prices. In the presence of some divalent metals or by lowering the pH, these renewable biopolymers can readily form hydrogels, solvogels and aerogels, characterized by high surface areas, good mechanical properties, tolerance to different media, and easy manageability. In the last years, alginate gels have been gradually used as supports for a varied range of active chemical species in heterogeneous catalysis and as solid acid Brønsted catalyst. In this context, the present work contributes to broaden the use of alginate gels in asymmetric heterogeneous catalysis, exploiting the peculiar features of this class of natural biomaterials. In the first part of this study, the use of alginate gel beads as supports to prepare a heterogenized version of an amino Cinchona alkaloid for asymmetric Michael addition is described. In contrast with the classical immobilization via covalent attachment in oil-derived support, our approach was the immobilization of the organocatalyst using non-covalent interactions. The results presented here demonstrate that the adsorption of a representative Lewis base organic catalyst (9-amino-9-deoxy epi-quinine, QNA) takes place with high yields onto acidic alginate gels (AGs) using a very simple and straightforward protocol. This protocol is robust and fully reproducible. The resulting chiral solvogel beads (QNA@AGs) are active as heterogeneous catalysts in the addition of aldehydes to nitroalkenes, affording the corresponding adducts in good yields and moderate to excellent diastereo- and enantio-selectivities. In these reactions, the carboxylic functions of the biopolymer act as both acidic co-catalyst and non-covalent anchoring site for the tertiary amine catalyst (as observed by IR spectroscopy). The use of heterocationic gels, derived from alkaline earth metal gels by partial proton exchange, provided materials with better mechanical properties and higher porosities, ultimately resulting in higher catalytic activities. The alginate gels were also assessed as a possible way of transfering chirality from the support to a reaction outcome. The Friedel-Crafts alkylation of nitroalkenes with indoles was selected as a model reaction to evaluate preliminarily the enantio-induction by metal Lewis alginate gels. The library of alginate gels tested is active in the benchmark reaction. The Cu and Ba- alginate gels afford good activity and the enantiomeric-induction is proved, obtaining moderate enantiomeric excesses under the optimized reaction conditions. Furthermore, these two metals allow access to both enantiomers of the products, an important aspect given that only one enantiomeric form of alginates is available. Finally, the heterogeneous nature of the catalyst is proved using Cu-alginate gels. The full recyclability is demonstrated, by showing that Cu-alginate gels can be recovered and recycled without loss of stereochemical activity for at least five reaction cycles. This work represents the first utilization of alginates, abundant and renewable biopolymers, as gel supports/media for asymmetric organocatalytic processes and the first example of induction of enantioselectivity for a C-C bonding reaction with interest in the fine chemical industry

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

Paints and varnishes industry is a well known sector of chemical industry and its importance is due to the need of surfaces colouring and protection (metals, wood, concrete) from many natural or artificial chemical or physical agents. This work is based on the formulation of new graphene-based paints and the analysis of their physical and chemical properties. Graphene is the bidimensional sp2 carbon nanomaterial with extraordinary properties as electron mobility, thermal conductivity, mechanical strength and large surface area [ (1), (2), (3), (4), (5) ]. Due to these properties, it’s used as additive in paints formulations to improve mechanical properties. Graphene-XT produces graphene by Liquid Phase Exfoliation (top-down approach) with a mechanical exfoliation in water environment, using only graphite and a non-toxic exfoliating agent/solvent, avoiding the common toxic solvents as 1-methyl-2pirrolidone (NMP) or cyclopentanone (CPO). Self-produced graphene was added to two types of paint to obtain products with different properties one from each other. In particular acrylic and teflon paints were used as bases with the addition of powder-graphene/graphene-ink. During this experimental thesis, three graphene-based paints were formulated: the first with the goal of improving hardness, adhesion, lubricant properties and mechanical resistance of the virgin teflon paint; the second was an adhesive and electrically acrylic conductive paint; the third was a formulation that increases some mechanical performances of a virgin acrylic paint. All the formulations were created and tested inside Graphene-XT laboratory, except for some test on the first formulation (third-part requested product).

The CO2 global average concentration has grown at an alarming rate in the last decade reaching 413 ppm in July 2021, positioning as the primary driver of climate change. The production of the major plastic materials globally produced still rely on fossil fuels, contributing to the release of CO2 in the atmosphere. It is in this contest, that bioplastic industry, particularly PHAs production brings many ecological advantages. PHAs are microbial synthetized polyesters polymers which are both biobased and biodegradable. They are versatile materials, whose properties, hence their applications, depend on their monomer composition, molecular weight and microstructure. This work proposed a more cost-effective and novelty approach, analysing the possibility to produce PHAs by C. aurantiacus, a photosynthetic non-sulphur green bacterium, which has a highly metabolic versatility. In fact, C. aurantiacus can grow in aerobic and anaerobic conditions, heterotrophically with several organic sources and autotrophically with CO2 only as the sole carbon. This was an exploratory work with the aim to evaluate the bacterium capacity to accumulate PHA under anaerobic conditions. Furthermore, new methodologies needed to be implemented and basic operating conditions were tested such as the inoculum-medium ratio, the correlation between OD and cdw and the state of the inoculum. Its growth was first characterized in a rich medium with glycyl-glycine and sulphide, different light intensities and temperatures. Meanwhile, it was possible to evaluate different media impact on its growth, PHA accumulating capacity and pigment synthesis, observing promising results from inorganic media and mixotrophic growth. Moreover, new microorganisms have been isolated from phototrophic mixed culture bioreactor to enlarge the laboratory library of phototrophic microorganisms capable of producing PHAs from inorganic carbon source, revealing an almond-shape purple bacteria able to accumulate PHA.

During this century, rapid population growth has led to an increased exploitation of oil and nuclear power to satisfy energy demands. This situation has created a growing tension between the deteriorating condition of the natural environment and the needs of society. Several research projects have sought to improve the situation through the development of innovative products and eco-friendly technologies: for example, the purification of the gaseous emissions emitted by industrial sources, or the manufacture of vehicles using sunlight as a renewable and clean energy. In addition, newly created materials are able to reduce air pollutants (organic and inorganic) through the process of photocatalysis, which consists of using solid semiconductors able to oxidize harmful substances until complete mineralization. In this context, the production of photocatalytic building materials could constitute a very interesting solution, and become an integral part of the strategy to reduce environmental pollution. Titanium dioxide (TiO2) is one of the most common photocatalytic materials. It can be used in many fields of application, including the building industry. The combination of titanium dioxide with cement makes it possible to obtain a binder that has both traditional properties, such as mechanical strength and durability, and new properties allowing the preservation of the environment and the conservation of the aesthetic value of the buildings. For instance, researchers have managed to create a material capable of accelerating the oxidation of the organic pollutants that are deposited on the external walls of the buildings. This dissertation focused on the design, synthesis and characterization of a new family of titanium dioxide 1D, 2D and 3D nano-systems, doped with lithium and some transition metals in order to decrease the band gap and to enable visible light photoactivation even in indoor conditions. The NPs samples showed an increment of the relative surface areas that was better than the increments observed in all the nanosheet samples (446 m2/g-1). The use of lithium, cobalt, cerium, and tungsten ions as dopants was evaluated through the UV-Vis absorption technique. The results showed both an increased absorption in the visible range and a decrease of band gap for the doped samples in comparison to the sample of pure TiO2. We used several methods to evaluate the photocatalytic efficiency of all the nanoparticles and nanosheets we produced. The Li-Co and Li-Ce doped nanoparticles showed very good results both in water solution and in gas phase. The photocatalytic activity of our nanosystems was comparable with the standard samples under UVb light, but the doped NPs, in particular those doped with Au@TiLi(5) and TiLi(5)Co(5), showed better results under visible light than the control samples. Our new synthesis method achieved very interesting results. It allowed us to obtain nanoparticles, nanosheets, xerogels, and aerogels covered with Li+ ions in place of the H+ ion at the surface in order to maintain them in a good dispersion in solution. In order to evaluate the toxicity of the NPs, a comparative study on human lung cells and E. coli cells was carried out in vitro. All the analyzed nanoparticles exhibited different photocatalytic activities for human cells and bacteria, in particular under irradiation. Some transition metal ions doped nanoparticles exhibited cytotoxicity even in absence of illumination, a phenomenon that was probably caused by their dopant content. The use of such systems could constitute a risk for human health; however, once inhaled, the lack of illumination within the human body could reduce such a risk, and for TiLi and Au@TiLi(5) groups the danger is virtually absent. The toxicity on E. coli cells is significantly higher in almost all cases. In the case of the TiLiCo group, in particular, there is a high contrast between the low toxicity for human cells and the high toxicity for E. coli.

Fossils fuels are highly demanded in everyday life domestically or industrially. Fossil fuels are finite resources and they are rapidly depleting, as such alternative renewable feedstocks are sought to replace fossil fuels. Tall oil from paper processing and cashew nut shell liquid from the cashew nut industry are the two major renewable sources we studied, they are both waste byproducts, and have the potential to be converted into value-added materials. Tall oil from the paper industry mainly contained tall oil fatty acid, and under isomerising methoxycarbonylation with palladium catalyst, dimethyl 1,19-dimethyl nonadecanedioate can be obtained. This difunctional ester, dimethyl 1,19-dimethyl nonadecanedioate, is converted to diols, secondary and primary diamines by a hydrogenation reaction with ruthenium complexes of 1,1,1-tris(diphenylphosphinometyl)ethane (triphos) as catalysts in the presence of water, amine or aqueous ammonia respectively. In the case of aqueous ammonia it is necessary to use a two step reaction via diol to obtain 1,19-diaminononadecane. Diesters, diols and diamines are useful precursors for the synthesis of polyesters and polyamides. Difunctional substrates with 8-19 carbon chains are all tolerated under the reaction conditions and are successfully converted to the corresponding diols and diamines in high yields. Under similar hydrogenation conditions with the same ruthenium catalyst, cyclic products were predominantly produced with decreased chain length. N-heterocycles, which are important building blocks for the synthesis of drug molecules, were formed from the hydrogenation of diesters with 4-7 carbon chains in the presence of an amine. Another polymer precursor, ε-caprolactam, which is the precursor for Nylon 6, is obtained in a reasonable yield from both adipic acid and adipate esters together with aqueous ammonia in the presence of ruthenium catalyst. Cashew nut shell liquid was also converted into useful medical drugs, such as norfenefrine, rac-phenylephrine, etilefrine and fenoprofene in reasonable yields. Most of these drug molecules have been formed from 3-vinylphenol by catalytic hydroxyamination followed by methylation or ethylation. 3-Vinylphenol was synthesised from cardanol by ethenolysis to 3-non-8-enylphenol followed by isomerising ethenolysis, whilst the N-alkylation reactions used methyl or ethyl triflate to avoid dialkylation. Fenoprofene was formed by firstly O-phenylating cardanol then ethenolysis followed by isomerising ethenolysis to form 1-phenoxy-3-vinylbenzene. Methoxycarbonyation followed by hydrolysis formed the final product in good yield. Our methods start from renewable waste materials and avoid unpleasant reagents in the original stoichiometric synthesis of those drugs, for example, cyanide is no longer essential for the synthesis of fenoprofene.

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009.
Committee Chair: Ragauskas, Arthur; Committee Member: Bunz, Uwe; Committee Member: Cairney, John; Committee Member: Collard, David; Committee Member: Singh, Preet. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Les résines phénoliques, sont entre autres utilisées dans l’industrie du bois pour la fabrication de panneaux de particules ou de contreplaqués, après des étapes d'encollage, d'imprégnation et/ou de pressage à chaud. Elles sont principalement obtenues par polymérisation par étapes (polycondensation) à partir de formaldéhyde et de phénol. Ces deux matières premières de base sont actuellement des produits issus de la pétrochimie.Ce travail de thèse Cifre, en partenariat avec la société Rolkem, spécialisée dans la conception et la fabrication de résines phénoliques de type résol, a pour objectif la réduction de l’utilisation de matières pétrochimiques via la substitution du phénol par une bioressource telle que la lignine. Cette dernière a une structure phénolique et une similarité structurelle avec le réseau des résines phénoliques, elle est abondante dans la nature et disponible. Pour atteindre l’industrialisation de ces nouvelles résines biosourcées, une étude sur la compréhension des mécanismes réactionnels qui gouvernent le procédé a été menée avant d’optimiser le protocole permettant l’incorporation de la lignine dans les résines.Il a été possible de remplacer jusqu’à 50%m du phénol par de la lignine organosolve et de réduire la concentration initiale en formaldéhyde. En utilisant une lignine Kraft il a été possible de remplacer jusqu’à 75%m du phénol et de réduire jusqu’à 30%m du formaldéhyde utilisé, par rapport aux résines classiques de référence, tout en respectant le cahier des charges imposé par Rolkem. Ces résultats ont été possibles grâce à des suivis cinétiques des procédés et des études de réactivité de la lignine. Grâce à ces travaux de thèse, le transfert d’échelle des résines biosourcées du laboratoire au pilote industriel a été possible, tout en respectant les contraintes industrielles telles que la productivité, la qualité, la sécurité et l’environnement. De plus, les essais industriels de collage de contreplaqués réalisés sont conformes aux prérequis.En complément des objectifs fixés par le projet, et de manière plus académique, la réactivité de la lignine vis-à-vis du formaldéhyde a été étudiée en chauffage conventionnel et sous irradiation microonde. Cette étude complémentaire permet de corréler la réactivité lignine-formaldéhyde et mode de chauffage et d’atteindre spécifiquement des produits issus de réactions d’addition ou de condensation
Phenolic resins, may be used in the wood industry for the manufacture of particle boards or plywood, after gluing, impregnation and/or hot-pressing steps. They are mainly obtained by step polymerization (polycondensation) from formaldehyde and phenol. These two raw materials are currently petrochemicals.This thesis work, supported by Rolkem, a company specialized in the design and manufacture of resol type phenolic resins, aims to reduce the use of non-biobased materials by replacing phenol with lignin exhibiting a phenolic structure and a structural similarity with the network of phenolic resins. Lignin is abundant in the environment and easily available. To achieve the industrialization of these new biobased resins, a study on the understanding of the reaction mechanisms has been carried out to favor the incorporation of lignin within the resins. It has been possible to replace up to 50wt.% of the phenol with organosolve lignin and to reduce the initial concentration of formaldehyde at the same time. 75wt.% substitution has been achieved using a Kraft lignin by reducing up to 30wt.% of the formaldehyde concentration as compared to conventional resins. The new biobased resins respect the Rolkem specifications. Thanks to this work results, the scale transfer of biobased resins from the laboratory scale to the industrial pilot was possible, while respecting industrial constraints such as productivity, quality, safety and environment. In addition, the industrial plywood bonding tests were in accordance with the prerequisite.In addition to the above objectives the reactivity of BiolignineTM with formaldehyde has been studied under conventional heating and microwave irradiation. This complementary study allows the correlation of the lignine-formaldehyde reactivity and the heating modes to specifically reach products resulting from addition or condensation reactions

L'utilisation de matériaux renouvelables est considérée comme l'un des points clés du développement durable. Les glucides sont facilement biodégradables et ont tendance à se dégrader dans les environnements biologiquement actifs. L'hémicellulose (HC) est l'un des polysaccharides les plus courants, représentant environ 20 à 35% de la biomasse lignocellulosique, et n'a pas encore trouvé sa place dans de larges applications industrielles comme la cellulose, autre ressource forestière. L'hémicellulose est un hétéro-polysaccharide. C'est aussi un substitut vert pour les polyols issus du pétrole ainsi qu'un substitut non alimentaire des polyols d'amidon. Les objectifs de ce projet sont le développement d'une stratégie optimisée pour l'extraction de l'hémicellulose et son utilisation dans les biomatériaux à forte valeur ajoutée. L'extraction de l'hémicellulose aurait un grand potentiel comme matière première de la nouvelle bio-économie. Pour étendre ses applications au domaine porteur des hydrogels, comme aux revêtements et adhésifs sensibles aux stimuli, des réseaux de polymères ou des systèmes de relargage de médicaments, les propriétés de l'hémicellulose ont été modifiées en introduisant sur sa chaîne principale des groupes réactifs pour le rendre réticulable réversiblement par la réaction de Diels-Alder. Par cette approche, le potentiel de remplacement des matières premières dérivées du pétrole par des ressources renouvelables pour la production de matériaux polymères biodégradables est important du point de vue sociétal et environnemental
The increased use of renewable materials is considered as one of the key issue of the sustainable development. Carbohydrates are readily biodegradable and tend to degrade in biologically active environments. Hemicelluloses (HC) are one of the most common polysaccharides next to cellulose and chitin, representing about 20-35% of lignocellulosic biomass, and have not yet found broad industrial applications as does cellulose. Hemicellulose is a hetero-polysaccharide and a green substitute for petroleum based polyols and is a non-food-based substitute for starch polyols. The aims of this project are to develop an optimized strategy for the extraction of hemicellulose and the use of the extracted hemicellulose in value-added biomaterials. The extraction of hemicellulose would have great potential to supply raw materials for the new bio-economy. To expand its applications to the field of stimuli-responsive hydrogels, coating and adhesives, polymer networks, as well as drug-delivery systems, the properties of hemicellulose were functionalized by introducing reactive groups onto its main chain to reversibly crosslink it by the Diels-Alder reaction. Hemicellulose based materials were prepared and characterized for their suitable application. Finally, the worldwide potential demand for replacing petroleum-derived raw materials by renewable resources in the production of valuable biodegradable polymeric materials is significant from both social and environmental viewpoints fuel and will predominate in the coming periods

Les microalgues sont l’une des ressources renouvelables les plus prometteuses pouvant constituer une alimentation durable future. Grâce à leur diversité de métabolisme, ces microorganismes sont capables de synthétiser une vaste gamme de composés d’intérêt à haute valeur nutritionnelle. Cependant, leur consommation reste limitée du fait de leurs caractéristiques organoleptiques intrinsèques peu attrayantes. Afin de répondre à cette problématique et de lever les verrous, les travaux de cette thèse ont porté sur la mise au point d’un procédé de production d’ingrédient alimentaire à partir de spiruline.Une méthode verte et innovante faisant intervenir la technologie ultrasonore pour l'extraction de protéines à partir d'Arthrospira platensis a été proposée dans une première partie. Il s’agit de la manothermosonication (MTS). Le recours à un plan d’expérience a permis d’optimiser les paramètres d’extraction ; et une modélisation mathématique ainsi que des investigations microscopiques ont mené à une compréhension des phénomènes de transfert de masse d’une part et des effets structurels des ultrasons sur les filaments de spiruline d’autre part. Selon les résultats expérimentaux, la MTS a permis d'obtenir 229 % de protéines en plus (28,42 ± 1,15 g / 100 g MS) par rapport au procédé classique sans ultrasons (8,63 ± 1,15 g / 100 g MS). Avec 28,42 g de protéines pour 100 g de spiruline dans l'extrait, un taux de récupération des protéines de 50 % a été atteint en 6 minutes effectives avec un procédé MTS continu. Partant de ces résultats prometteurs, des pistes d’extrapolation ont été étudiées afin de proposer des outils d’aide à la décision pour l’industrialisation du procédé. Ainsi une procédure d’analyse des risques (HACCP & HAZOP), une étude de coût ainsi que l’impact environnemental du procédé ont été développés dans une seconde partie de ces travaux. Enfin, des voies de valorisation des co-produits d’extraction ont été présentées dans une approche de bioraffinerie
Microalgae are one of the most promising renewable resource for future sustainable food. Thanks to their diversity of metabolism, these microorganisms can synthesize a wide range of compounds of interest with high nutritional value. However, their consumption remains limited because of their intrinsic organoleptic characteristics unattractive. To tackle this problem and to overcome these barriers, this thesis was focused on the development of a production process of food ingredient from spirulina.A green and innovative method using ultrasonic technology for the extraction of proteins from Arthrospira platensis was proposed in a first part. This is the manothermosonication (MTS). The use of an experimental plan made it possible to optimize extraction parameters; and mathematical modeling and microscopic investigations led to an understanding of the mass transfer phenomena on the one hand, and the structural effects of ultrasound on spirulina filaments on the other hand. According to the experimental results, MTS allowed to obtain 229 % more proteins (28.42 ± 1.15 g / 100 g DW) compared to the conventional method without ultrasound (8.63 ± 1.15 g / 100 g DW). With 28.42 g of protein per 100 g of spirulina in the extract, a protein recovery rate of 50% was achieved in 6 minutes with a continuous MTS process. Based on these promising results, extrapolation tracks have been studied in order to propose decision support tools for process industrialization. Thus, a risk analysis procedure (HACCP & HAZOP), a cost study as well as the environmental impact of the process were developed in a second part of this work. Lastly, ways of exploiting by-products have been presented in a biorefinery approach

This thesis is about sustainability within chemistry, the so-called, green chemistry. With this work  I seek to combine green chemistry with sustainable  development  and find methods for teaching green chemistry in a laboratory environement.  I have designed  and tested two labs with ingredients of green  chemistry and sustainable development in my study. I wanted to determine if my design model  leads to conception for the students. The students have through forms and interviews declared their perspective on the education and their conception. In a laboratory environment the pros of a laboratory way of work should be recognized. Pre- and post-work puts the lab in a context. The students understand the concepts better if they are allowed to test their knowledge in a discussion. The teachers role in the discussion should be to lift the level of the discussion by controlling the conversation and in a constructiveway contribute to making the discussion move forward whenever necessary.
Denna uppsats behandar hållbarhet inom kemi, den så kallade gröna kemin. Med arbetet söker jag förena grön kemi med hållbar utveckling och hitta metoder för att undervisa grön kemi i en laborativ miljö. I undersökningen har jag designat och testat två laborationer med inslag av grön kemi och hållbar utveckling. Jag ville undersöka om undervisningsmodellen leder till en begreppsutveckling hos studenter och elever. Studenterna/eleverna har genom enkäter och intervjuer uttalat sig om dels sina egna kunskaper och dels om undervisningens inslag och dess bidrag till deras begreppsutveckling. I ett laborativt sammanhang bör fördelarna med ett laborativt arbetssätt utnyttjas. Förarbete och efterarbete ger laborationen ett sammanhang. Studenten/eleven förstår begreppen bättre om de får testa sina kunskaper i en diskussion. Lärarens roll i diskussionen bör vara att lyfta diskussionsnivån genom att styra samtalet och på ett konstruktivt sätt bidra till att föra diskussionen framåt när det är nödvändigt.

Neste trabalho, fracionou-se e tratou-se a argila Brasgel. Esta argila foi pilarizada em vários estágios de facionamento e/ou tratamento com 5 meq de Al / g de argila: (i) Al-PILC, a argila passou por todos os estágios de fracionamento e tratamento (ARG), (ii) Al-PILCFe, a argila não passou pela etapa de retirada de Fe livre (ARGFe) e (iii) Al-PILCFe/silte, a argila não passou pelas etapas de retirada de silte e Fe livre (ARGFE/silte). Em análise por DRX observou-se que as Al-PILCs apresentaram uma distância basal maior que as argilas de partida. A análise textural indicou que as argilas Al-PILCs e ARGs são materiais mesoporosos, com poros do tipo fenda estreita e do tipo fenda, respectivamente. Além disso, as Al-PILCs apresentaram área superficial razoavelmente maior que as ARGs correspondentes. Outras análises feitas nas argilas foram: teor de Si, Fe e Al; CTC; FTIR; TGA e TGD. As argilas Brasgel pilarizadas foram usadas como catalisador na reação de isomerização do óxido de estireno em hexano sob refluxo. A reação foi seletiva na formação de fenilacetaldeído. As argilas Al-PILCFe e Al-PILCFe/silte apresentaram melhor desempenho catalítico (100 % de conversão em 20 min de reação). Assim, as argilas Brasgel pilarizadas se apresentaram como uma Tecnologia Limpa na reação de isomerização do óxido de estireno ao fenilacetaldeído. Palavras-chave: Desenvolvimento Sustentável. Tecnologia Limpa. Química Verde. Argilas Pilarizadas. Isomerização de Epóxidos.
This work, the Brasgel clay was fractionated and treated. The clay was pillared in several stages of fractionation and / or treatment with Al 5 meq / g of clay: (i) Al- PILC, the clay has passed through all stages of treatment and fractionation (ARG), (ii) Al-PILCFe, the clay would not pass the step of removal of free Fe (ARGFe) and (iii) Al-PILCFe/silt, clay has not gone through the steps of removing silt and free Fe (ARGFE/silt). XRD analysis showed that the Al-PILCs showed a basal spacing greater than the starting clays. The textural analysis indicated that the Al-PILCs and ARGs are mesoporous materials, with pore narrow slit type and slit type, respectively. Moreover, the Al-PILCs showed reasonable surface area greater than the corresponding ARGs. Other analyzes were made on clays: the content of Si, Fe and Al; CEC, FTIR, TGA and TGD. Brasgel pillared clays have been used as catalyst in the isomerization reaction of the styrene oxide in refluxing. The reaction was selective for the formation of phenylacetaldehyde. Al-PILCFe and Al-PILCFe/silt clays showed better catalytic performance (100% conversion in 20 min of reaction). Thus, the pillared clays Brasgel presented as a Clean Technology in the isomerization reaction of styrene oxide to phenylacetaldehyde. Keywords: Sustainable Development. Clean Technology. Green Chemistry. Pillared Clays. Isomerization of Epoxides.

De nos jours, l'industrie minière a connu une activité intense dans le domaine du développement de réactifs et additifs pour le traitement d'une grande variété de minerais. En outre, les recherches actuelles montrent un intérêt croissant pour les additifs de type collecteurs, dépresseurs ainsi que les agents chélatants, au regard de leur performance et leur efficacité au niveau industriel, et plus particulièrement dans l'industrie des phosphates.L'objectif ultime de ce travail de thèse est de développer de nouveaux réactifs et additifs « fait-maison » afin de soutenir et d'accompagner les développements futurs de l'industrie des phosphates au Maroc, et d'ouvrir ainsi de nouvelles perspectives. En conséquence, nos travaux de recherche sont concentrés sur la synthèse et la validation des performances de réactifs et additifs à l'échelle laboratoire, pilote et industrielle. Dans ce contexte, des agents, appartenant à des classes chimiques différentes, ont été conçus pour l'enrichissement des phosphates pauvres en P2O5 et pour l'élimination de certains métaux lourds. En effet, avec l'augmentation de la population mondiale, la demande croissante en engrais phosphatés dépourvus de métaux lourds, il devient urgent de faire un focus sur l'exploitation des phosphates à faible teneur en P2O5 et sur l'élimination des métaux lourds. Dans ce cadre, nous avons développé et évaluer différents agents organophosphorés, faits maison, lors des procédés de flottation inverse et de précipitation. Ces agents chimiques se sont avérés très efficaces et ont livrés des rendements élevés. Au cours de ces travaux de thèse, nous nous sommes également intéressés à la conception, la synthèse et l'évaluation de nouveaux acides bis-phosphoniques et de dihydropyrimidines dans le but de valoriser et diversifier le portefeuille de produit à base de P, en s'inscrivant dans le cadre d'une chimie verte et durable
Nowadays, the mining industry has seen intense activity in the development of reagents and additives for processing a wide variety of minerals, with a special focus on collectors, depressants, as well as chelating agents. Indeed, these agents demonstrated high performances at industrial level, and more particularly in the phosphate industry.The ultimate goal of this thesis work is to develop new “Home Made” reagents and additives in order to support ongoing developments in the phosphate industry in Morocco and to open new perspectives. Accordingly, our research work is focused on the synthesis and performance evaluation of reagents and additives at laboratory, pilot and industrial scales. In this context, agents, belonging to different chemical classes, have been designed for P2O5 low-grade phosphate beneficiation as well as for heavy metals removal. Indeed, with the increase in the world population and the growing demand for free-heavy metals phosphate fertilizers, it is of utmost importance to focus on the exploitation of P2O5 low-grade phosphates and the elimination of heavy metals. In this context, we developed and evaluated various home-made organophosphorus agents during reverse flotation and precipitation processes. These chemicals have proven to be very effective and have produced high yields. Furthermore, during this thesis work, we were also interested in the design, synthesis and evaluation of new bis-phosphonic acids and dihydropyrimidines, with the aim of enhancing and diversifying the portfolio of P-based products, within the framework of green and sustainable chemistry

The present Ph.D. thesis provides some examples of innovative 2nd generation catalytic processes for the conversion of renewable raw materials into green value-added chemicals. In particular, D-glucose and some its derivatives, all ideally representing waste materials of dedicated biomasses, agricultural residues, or solid organic urban waste exploitation in the biorefinery plant, were converted into useful chemical building-blocks. After a brief introduction to the topic and the description of the experimental method, each chapter of the work is based on one or more scientific articles either published or submitted. Among the possible catalytic reactions, the hydrogenation, oxidation and hydrodeoxygenation were investigated: for this purpose, several novel catalysts were synthetized, tested and characterized. The catalysts were made from precursor solutions with the incipient wet impregnation method or with the solution combustion synthesis, depending by the catalyst type. The conversion of glucose and some glucose-derivatives was typically performed under gentle operative conditions and in aqueous mean. Pt-based catalysts were tested for glucose conversion to adipic acid in a two-step process carried out in water solution without any pH control by investigating the effect of a series of supporting materials (active carbon, alumina, silica and ceria). The process consisted in the D-saccharic acid (SacA) production by D-glucose catalytic wet air oxidation followed by a hydrodeoxygenation treatment of SacA to adipic acid (AA) with the same catalyst. The main limit of using Pt for D-glucose oxidation is represented by the catalyst inhibition operated by the first product of the reaction, the gluconic acid (GluA), which prevents the consecutive reaction of SacA formation, but a deeper investigation of the reaction scheme allowed us to assess that over Pt/alumina the consecutive oxidation of gluconic acid to SacA is slightly favored under uncontrolled pH too.We have demonstrated that a 5.2 wt.% Pt on γ-alumina sample, the catalysts presenting the larger amount of strong Brønsted acid sites, was the best material for obtaining SacA (with a molar yield of about 13.5%); afterward, by performing the halogen-promoted hydrodeoxygenation of the resulting solution, the SacA was quantitatively converted into AA (and thus the overall adipic acid molar yield from glucose was about 13.0%). Effectively, The efficient conversion of common biomass derivatives, as D-glucose, into value-added chemicals has received a great deal of attention in the last few years. Several heterogeneous catalytic systems, characterized by noble metals, have already been investigated for the Catalytic Wet Air Oxidation (CWAO) of derived biomass. Nevertheless, the redox effect of such catalysts on biobased compounds has not been described in detail. In the present thesis, some perovskite type oxides (Fe, Co, Mn) that present high redox properties and stability under hydrothermal conditions have been tested to establish their ability to convert D-glucose into C6 aldaric acid, lactic acid (LacA) and levulinic acid (LevA). The influence of the reaction temperature, and the affinity of the catalysts to hydrogen and oxygen on the distribution of the liquid products have been investigated. In the best conditions, 50.3 mol.% and 69.5 mol.% of lactic and levulinic acid have been obtained by employing LaCoO3 and LaMnO3, respectively. Apart from the oxidative effect, which has led to several oxidation products, a high reductive effect of the catalysts has enabled the conversion of some key intermediates, such as pyruvic acid (PyrA) and hydroxymethylfurfural (HMF), into the desired products. LaMnO3, which has resulted to be the most oxidizable/reducible catalyst over a low temperature range, has shown the best performance of the studied perovskite type oxides; it has been found to promote the conversion of hydroxymethylfurfural to levulinic acid and to give the highest overall molar yield. Moreover, performing catalysts have been synthetized through incipient wet impregnation and tested for cis,cis-muconic acid (ccMA) hydrogenation to adipic acid. Before the hydrogenation, the investigation on the solubility of ccMA dissolution in different polar solvents has been carried out by characterizing and modelling the dissolution as a function of temperature. Water, ethanol, 2-propanol and acetic acid have been investigated as solvents in the range temperatures from a 298.15 to 348.15 K. Owing to the absence of ccMA solubility data, the reliability of the adopted experimental set-up was validated comparing published and experimental solubility data of a similar compound, that is, AA. From the results, it has emerged that the employed system is appropriate for the determination of molar fractions of an organic compound dissolved in polar solvents. The molar fraction and temperature were correlated using the Apelblat equation model, which is applied for the mathematic fitting of experimental data. A total relative average deviation of 3.54% was obtained for the experimental results and the solubility data obtained with the model, thus attesting the adequacy for this study. The use of Apelblat equation also allowed to determine the apparent molar enthalpy and molar entropy of dissolution. The dissolution of ccMA in water, ethanol, 2-propanol and acetic acid, over temperatures ranging from 298.15 to 348.15 K, has been shown to be endothermic. The activity of Pt-based catalysts has been compared with a Ni-based catalyst at a gentle condition. A supported 14.2 wt.% Ni on γ-alumina converted 100% of muconic acid, yielding 99.4 mol.% of AA. Finally, the oxidative cracking of 5-keto-L-aldonic acids to tartaric acid (TarA) was successfully performed at room temperature and atmospheric pressure in a carbonate buffer (pH = 10.34), by employing various V-based catalysts. The performance of the novel heterogeneous V-based catalysts was compared with the one of a conventional homogeneous system. The effect of the catalysts was obvious and 2%VOx/ZrO2 was found to be the best catalyst for the 5-keto-aldonic acids conversion to tartaric acid. The tartaric acid selectivity was equal to 74.5% and 44.3% starting from the 5-keto-D-gluconic acid (5kGl) and 5-keto-L-galactonic acid (5kGa), respectively. The best performances in terms of tartaric acid selectivity were obtained at the beginning of reaction, and about one fourth of the carbon moles were converted into tartaric acid after 24 h of reaction. The substrate was entirely converted after 24 h indicating that several by-products were also produced during the reaction. So, an overall reaction pathway was supposed and the effect of the vanadium structure to the catalytic activity was hypothesized. Moreover, the reaction mechanism of the 5-keto-aldonic acids conversion to tartaric acid promoted by the anchoring VOx-support bond was described.

Le furfural, identifié comme l'un des 30 principaux produits chimiques biologiques, est une molécule importante en terme de chimie verte et développement durable. L'objectif de ce travail de doctorat est de réaliser la synthèse et la conversion du furfural en flux continu et par lots. Ici, nous avons développé des méthodes plus éco-efficiente pour la synthèse du furfural, et valorisé le furfural en produits à haute valeur ajoutée, tels que le 2-furonitrile, l'alcool furfurylique, etc... Plusieurs questions clés ont été identifiées afin de concevoir des processus plus écologiques que les processus actuels. En détail, des expériences de synthèse du furfural ont été réalisées dans l'eau pure ou dans un mélange eau-solvants organiques lorsque des co-solvants (verts ou écologiques) sont nécessaires. L'irradiation par micro-ondes a été choisie comme méthode de chauffage pour accélérer le processus de déshydratation, et un réacteur à flux continu à micro-ondes a également été utilisé pour améliorer la productivité du furfural. En partant du furfural pour produire des produits chimiques à haute valeur ajoutée, des réacteurs à flux efficace, tels que Pheonix, H-cube Pro ainsi que des micro-ondes à flux continu avec micro-réacteur, ont également été identifiés comme des alternatives intéressantes pour améliorer la productivité des composés cibles. En conséquence, certains résultats prometteurs ont été obtenus du point de vue de l'industrie
Furfural, which has been identified as one of top 30 bio-based chemicals, is an important green platform molecule, The aim of this PhD work is to realize the synthesis and conversion of furfural in batch and continuous flow. Here, we developed sorne greener methods for furfural synthesis, and valorized furfural into high value-added products, such as 2-furonitrile, furfuryl alcohol etc. Several keys issues were identified in order to design processes greener than the current ones. ln detail, experiments for furfural synthesis were performed in water or in water and organic solvent when co-solvents (green or eco-friendly) are necessary. Microwave irradiation has been chosen as the heating method to accelerate the dehydration process, and microwave continuous flow reactor was also applied to improve furfural productivity. When starting from furfural to produce high value-added chemicals, efficient flow reactors, suc as Pheonix, H-cube Pro as well as microwave continuous flow With micro-reactor, were also identified as interesting alternatives to improve the productivities of target compounds. As a result, some promising results were obtained in the viewpoint of industry

Historiquement, l’industrie chimique est basée sur l’utilisation de ressources fossiles, mais depuis les années quatre-vingt-dix, des procédés alternatifs ont été développés afin d’être plus verts et de répondre aux questions environnementales concernant l’éco-responsabilité. Dans ce contexte, un travail collaboratif entre trois laboratoires académiques et la SAS PIVERT a émergé, afin de trouver de nouveaux hydrotropes biosourcés à partir de divers polyols, comme le glycérol par exemple qui est le sous-produit majoritaire lors de la production de biodiesel, avec une résistance aux hautes conditions salines. Un design particulier a été défini par notre partenaire physico-chimiste pour cette synthèse d’hydrotropes. Ainsi, pour obtenir ces composes, différentes approches ont été utilisées comme par exemple, une nouvelle méthode de méthylation utilisant du méthanol sub/supercritique avec une phase d’optimisation et d’exemplification de la réaction. Une autre méthode porte sur la transposition de l’alkylation réductrice de différents alcools utilisant des conditions de flux via l’utilisation du HCube Pro de chez ThalesNano, mais aussi d’une catalyse hétérogène pour l’obtention d’un panel large d’éthers
Historically, chemical industry was based on fossil ressources, but alternative processes have been developed since the nineteens to be green and to answer to the environmental eco-responsibility questions. In this context, a collaboration work between three public laboratories and the SAS PIVERT emerged to find new biosourced hydrotropes starting from various polyols – such as glycerol, main byproduct of the fuel production – and resistant to high saline conditions. A specific design was defined by our physico-chemical partner for the synthesis of hydrotropes. Differents approaches were used to obtain these compounds, such as a new method of methylation using sub/supercritical methanol with a phase of optimization, and another about the scope of the reaction that reduced the reaction steps. The transposition of the reductive alkylation of various alcohols was also realized – using a heterogeneous catalysis – with the obtention of various ethers, in continuous flow conditions, by the intermediate of the use of the HCube Pro from ThalesNano

[ES] En este trabajo de tesis doctoral, la investigación se ha centrado en el desarrollo de diferentes procesos catalíticos heterogéneos empleando materiales híbridos orgánico-inorgánicos porosos (MOFs y sílices funcionalizadas) y materiales orgánicos aromáti-cos (PAFs), que se han estudiado en diversas reacciones orgánicas. Tras la preparación de los MOFs en estudio, se han caracterizado sus propiedades estructurales y se han determinado sus centros activos en los clústeres metálicos (circonio, hafnio o cerio). La reactividad de estos MOFs y de los materiales híbridos sílice-aminas se ha estudia-do teniendo en cuenta sus centros catalíticos; estas reacciones se han optimizado lle-vando a cabo un estudio de los mecanismos de reacción. Finalmente, se han preparado sólidos homoquirales de tipo PAF que presentan el sistema binaftilo, cuya reactividad también ha sido probada. Más específicamente, en el capítulo 3 se ha estudiado la esterificación de amidas, que permite convertirlas en ésteres, grupos funcionales más versátiles. Esta transfor-mación se ha abordado desde la catálisis heterogénea via MOFs basados en circonio, hafnio y cerio de las series MOF-808, UiO-66 y MOF-801. El catalizador más eficien-te para la esterificación de amidas ha sido el MOF-808-Zr. Mediante análisis TGA y la adsorción de una molécula sonda básica (CO) estudiada utilizando espectroscopia FT-IR, se han determinado los centros ácidos de Lewis y Brönsted presentes en ellos. De los MOFs preparados en este trabajo, el MOF 808-Zr posee una menor conectividad de los clústeres metálicos y un mayor tamaño de poro mayor que el UiO-66 y el MOF-801; además, tiene el balance adecuado de centros ácidos y básicos de Brönsted y Lewis para activar los sustratos de la reacción. El alcance de la alcoholisis con n-butanol se ha extendido a un gran número de sustratos (amidas primarias, secundarias y terciarias; aromáticas y alifáticas). La reacción también se ha estudiado en condicio-nes no solvolíticas con alcoholes más complejos. El catalizador es estable durante la reacción y puede ser reutilizado fácilmente. El mecanismo de reacción en la esterifica-ción de benzamida con n butanol catalizada por MOF-808-Zr se ha investigado me-diante el análisis cinético empleando el modelo de LHHW y el estudio in situ de las interacciones moleculares por FT-IR. En el capítulo 4, se ha investigado la deuteración por intercambio isotópico deute-rio/hidrógeno catalizada por aminas soportadas en sílice comerciales empleando D2O como fuente de deuterio. Este procedimiento es aplicable a una gran gama de sustra-tos, como compuestos carbonílicos, sales de organofosfonio, nitrocompuestos e, inclu-so, hormonas esteroideas. La estabilidad del catalizador, SiO2-(CH2)3-NH2, se mantie-ne hasta en 10 usos de reacción sin pérdidas significativas de la actividad. Por último, en el capítulo 5, se afronta la síntesis y aplicación de PAFs homoquira-les donde se ha integrado el esqueleto del BINOL (1,1′-binaftil-2,2′-diol) y del BIN-BAM (1,1' binaftil-2,2'-disulfonimida) generando tres nuevos PAFs activos en catáli-sis asimétrica: PAF-3,3'-(S)-BINOL, PAF-6,6'-(R)-BINOL y PAF 3,3'-(S)-BINBAM. En concreto, el PAF-6,6'-(R)-BINOL ha demostrado su actividad catalítica en la reacción de alquilación de aldehídos aromáticos con dietil-zinc y el catalizador PAF-3,3'-(S)-BINBAM es activo en la reacción aldólica de Mukaiyama y la reducción del doble enlace de compuestos carbonílicos a,b-insaturados.
[CA] En aquesta tesi doctoral, la investigació s'ha centrat en el desenvolupament de dife-rents processos catalítics heterogenis emprant materials híbrids orgànic-inorgànics porosos (MOFs i sílices funcionalitzades) i materials orgànics aromàtics (PAFs), que s'han estudiat en diverses reaccions orgàniques. Després de la preparació dels MOFs en estudi, s'han caracteritzat les seues propietats estructurals i s'han determinat els seus centres actius en els clústers metàl·lics (zirconi, hafni o ceri). La reactivitat d'aquests MOFs i dels materials híbrids sílice-amines s'ha estudiat tenint en compte els seus cen-tres catalítics; aquestes reaccions s'han optimitzat duent a termini un estudi dels meca-nismes de reacció. Finalment, s'han preparat sòlids homoquirals de tipus PAF que presenten el sistema binaftilo, la reactivitat del qual també ha sigut provada. Més específicament, en el capítol 3 s'ha estudiat l'esterificació d' amides, que per-met convertir-les en èsters, grups funcionals més versàtils. Aquesta transformació s'ha abordat des de la catàlisi heterogènia via *MOFs basats en zirconi, hafni i ceri de les sèries MOF-808, UiO-66 i MOF-801. El catalitzador més eficient per a l'esterificació d'amides ha sigut el MOF-808-Zr. Mitjançant anàlisi TGA i l'adsorció d'una molècula sonda bàsica (CO) estudiada utilitzant espectroscopia FT-IR, s'han determinat els cen-tres àcids de Lewis i Brönsted presents en ells. Dels MOFs preparats en aquest treball, el MOF 808-Zr posseeix una menor connectivitat dels clústers metàl·lics i una major grandària de porus que el UiO-66 i el MOF-801; a més, té el balanç adequat de centres àcids i bàsics de Brönsted i Lewis per a activar els substrats de la reacció. L'abast de l'alcoholisi amb n-butanol s'ha estés a un gran nombre de substrats (amides primàries, secundàries i terciàries; aromàtiques i alifàtiques). La reacció també s'ha estudiat en condicions no solvolítiques amb alcohols més complexos. El catalitzador és estable durant la reacció i pot ser reutilitzat fàcilment. El mecanisme de reacció en l'esterifica-ció de benzamida amb n-butanol catalitzada per MOF-808-Zr s'ha investigat mitja-nçant l'anàlisi cinètica emprant el model de LHHW i l'estudi in situ de les interaccions moleculars per FT-IR. En el capítol 4, s'ha investigat la deuteració per intercanvi isotòpic deuteri/hidrògen catalitzada per amines suportades en sílices comercials emprant D2O com a font de deuteri. Aquest procediment és aplicable a una gran gamma de substrats, com a com-postos carbonílics, sals d'organofosfoni, nitrocompostos i, inclosa, hormones esteroi-dals. L'estabilitat del catalitzador, SiO2-(CH2)3-NH2, es manté fins a 10 usos de reac-ció sense pèrdues significatives de l'activitat. Finalment, en el capítol 5, s'afronta la síntesi i aplicació de PAFs homoquirals on s'ha integrat l'esquelet del BINOL (1,1′-binaftil-2,2′-diol) i del BINBAM (1,1'-binaftil-2,2'-disulfonimida) generant tres nous PAFs actius en catàlisi asimètrica: PAF-3,3'-(S)-BINOL, PAF-6,6'-(R)-BINOL i PAF 3,3'-(S)-BINBAM. En concret, el PAF-6,6'-(R)-BINOL ha demostrat la seua activitat catalítica en la reacció d'alquilació d'aldehids aromàtics amb dietil-zinc i el catalitzador PAF-3,3'-(S)-BINBAM és actiu en la reacció aldólica de Mukaiyama i la reducció del doble enllaç de compostos carbonílics a,b-insaturats.
[EN] In this Doctoral Thesis, the research has been focused on the development of different heterogeneous catalytic processes using hybrid porous organic-inorganic materials (MOFs and functionalized silicas) and organic aromatic materials (PAFs), which have been studied in various organic reactions. After the preparation of the MOFs under study, their structural properties have been characterised and their active centres in the metal clusters (zirconium, hafnium or cerium) have been determined. The reactivity of these MOFs and the hybrid silica-mine materials has been studied considering their catalytic centres; these reactions have been optimised by carrying out a study of the reaction mechanisms. Finally, homochiral PAF-type solids have been prepared with the binafil system, whose reactivity has also been tested. More specifically, the esterification of amides has been studied in Chapter 3. This reaction allows to convert the amides into esters, which are more versatile functional groups. This transformation has been approached from the heterogeneous catalysis via MOFs based on zirconium, hafnium and cerium of the MOF-808, UiO-66 and MOF-801 series. The most efficient catalyst for amide esterification has been MOF-808-Zr. Using TGA analysis and the adsorption of a basic probe molecule (CO) studied using FT-IR spectroscopy, the acid centres of Lewis and Brönsted present in them have been determined. Among the MOFs prepared in this work, MOF 808-Zr has a lower metal cluster connectivity and a larger pore size than UiO-66 and MOF-801; it also has the appropriate balance of acid and basic Brönsted and Lewis centres to activate the reaction substrates. The scope of n-butanol alcoholysis has been extended to a large number of substrates (primary, secondary and tertiary amides; aromatic and aliphatic). The reaction has also been studied in non-solvolitic conditions with more complex alco-hols. The catalyst is stable during the reaction and can be easily reused. The reaction mechanism in the esterification of benzamide with n-butanol catalysed by MOF-808-Zr has been investigated through kinetic analysis using the LHHW model and the in situ study of molecular interactions by FT-IR. In Chapter 4, the deuteration by isotopic deuterium/hydrogen exchange catalysed by commercial silica-supported amines using D2O as a source of deuterium has been investigated. This procedure is applicable to a wide range of substrates, such as carbonylic compounds, organophosphonium salts, nitro compounds and, even, steroid hormones. The stability of the catalyst, SiO2-(CH2)3-NH2, is maintained for up to 10 reaction uses without significant loss of activity. Finally, in Chapter 5, the synthesis and application of homochiral PAFs, in which the structure of BINOL (1,1′-binaftil-2,2′-diol) and BIN-BAM (1,1' binaftil-2,2'-disulfonimide) has been integrated, is discussed. Three new PAFs active in asymmetric catalysis has been generated: PAF-3,3'-(S)-BINOL, PAF-6,6'-(R)-BINOL and PAF 3,3'-(S)-BINBAM. In particular, PAF-6,6'-(R)-BINOL has demonstrated its catalytic activity in the alkylation reaction of aromatic aldehydes with diethyl zinc and the catalyst PAF-3,3'-(S)-BINBAM is active in the Mukaiyama aldolic reaction and the reduction of the double bond of carbonylic a,b-unsaturated compounds.
Villoria Del Álamo, B. (2021). Síntesis de catalizadores sólidos orgánicos e híbridos orgánicos-inorgánicos y su aplicación [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/163789
TESIS

Dissertação de Mestrado em Química apresentada à Faculdade de Ciências e Tecnologia
A noção de desenvolvimento sustentável «satisfazer as necessidades do presente sem comprometer a capacidade das gerações futuras de satisfazerem as suas próprias necessidades» foi introduzida na sociedade no início da década de 90. Possuindo uma ampla definição inclui diversas perspetivas, entre as quais a química sustentável e a engenharia sustentável. A química verde definida como a invenção, desenvolvimento e aplicação de produtos químicos e processos, para reduzir ou eliminar, o uso e a formação de substâncias perigosas à saúde humana e ao meio ambiente é uma parte da química sustentável em que se inserem os estudos apresentados nesta dissertação. A mecanoquímica, entendida como a área que estuda as transformações químicas promovidas pela ação mecânica, tem sido alvo de renovada atenção nos últimos anos devido à sua potencialidade para a promoção de reações sem a utilização de solvente eliminando, assim, uma das maiores fontes de desperdícios, de matérias primas e resíduos indesejáveis nos processos químicos. Desde a utilização imemorial do almofariz como “reator” para promover transformações por ação mecânica, vários equipamentos têm sido desenvolvidos para a aplicação de forças mecânicas em sólidos, contudo pela especificidade da aplicação, mantem-se a necessidade de desenvolver reatores dedicados à realização de reações de síntese química. Ao longo do trabalho apresentado nesta dissertação e em colaboração com o Laboratório de Energética e Detónica do Departamento de Engenharia Mecânica da Universidade de Coimbra desenvolveu-se um reator para síntese orgânica via mecanoquímica que se encontra em fase de finalização e de pedido de patente. A condensação de Claisen-Schmidt para a síntese de chalconas foi utilizada como reação modelo no processo de desenvolvimento e construção do reator. Nesta dissertação apresentam-se os estudos realizados na síntese via mecanoquímica de chalconas e porfirinas. A síntese via mecanoquímica revelou-se muito eficaz em ambos casos permitindo a obtenção destes compostos com rendimentos similares ou superiores a outros métodos descritos na literatura. Permitiu ainda reduzir ou eliminar a quantidade de solventes, reduzir os tempos de reação e efetuar a reação a temperatura ambiente dispensando aquecimento. As novas metodologias aproximam-se assim, aos princípios da química verde o que é evidenciado pela quantificação através das métricas, Fator-E completo e EcoScale, dos seus valores ótimos.
The notion of sustainable development 'meeting the needs of the present without compromising the ability of future generations to meet their own needs' was introduced into society in the early 1990s. Having a broad definition, it includes a number of perspectives, including sustainable chemistry and sustainable engineering. Green chemistry defined as the invention, development and application of chemicals and processes to reduce or eliminate the use and formation of substances hazardous to human health and the environment, is a part of sustainable chemistry which includes the studies presented in this dissertation. Mechanochemistry, understood as the area that studies the chemical transformations promoted by mechanical action, has been the subject of renewed attention in recent years due to its potential to promote reactions without the use of solvent, thus eliminating one of the major sources of waste, raw-materials and undesirable residues in chemical processes. Since the immemorial use of the mortar as a "reactor" to promote transformations by mechanical action, several types of equipment have been developed for the application of mechanical forces in solids, however due to the specificity of the application, the need remains for the development of appropriate reactors for carrying out chemical synthesis reactions. Throughout the work presented in this dissertation and in collaboration with the Laboratory of Energetics and Detonation of the Department of Mechanical Engineering of the University of Coimbra a reactor for organic synthesis via mechanochemistry was developed that is in the phase of finalization and patent application. The Claisen-Schmidt condensation for the synthesis of chalcones was used as a model reaction in the process of development and construction of the reactor. In this dissertation the studies carried out in the mechanochemical synthesis of chalcones and porphyrins are presented. Synthesis via mechanochemistry proved to be very effective in both cases allowing the formation of these compounds with yields similar or superior to other methods described in the literature. It also allowed to reduce or eliminate the amount of solvents, reduce the reaction times and carry out the reaction at room temperature. The new methodologies thus approach the principles of green chemistry, which is demonstrated by the quantification through the metrics, Full- E Factor and EcoScale, of their optimal values.

This doctoral work is focused on the sustainable valorization of cellulose and its derivable molecules, through the application of the hydrogenolysis technology, by using heterogeneous Pd-based catalysts, in order to achieve products with high-added values, such as chemicals and fuels. In particular, the study of hydrogenolysis has been conceived with a bottom-up approach starting from polyols, namely sorbitol (C6) and shorter polyols (C5-C2), to approach finally the cellulose, with the aim to unravel the reactivity and selectivity, and to understand the mechanism of reactions involved. This study is mainly devoted toward the investigation of the bimetallic co-precipitated Pd/Fe3O4 catalyst, therefore its textural and structural characteristics have been deeply elucidated through several characterization techniques (XRD, TEM, H2-TPR, XPS and EXAFS), in order to highlight the key factors that determine its unique catalytic performances observed. A comparison of the performance of the bimetallic Pd/Fe3O4 catalyst and that of the commercial Pd/C was also performed. The importance of the mechanical pretreatment of cellulose (e.g. ball milling) and the role of water in its hydrogenolysis were also assessed. The last part of this doctoral study was dedicated to the investigation of hydrogen donor (H-donor) molecules, such as limonene and 2-propanol, studying the conversion of cellulose, by using the bimetallic Pd/Fe3O4 catalyst. These reactions were performed in presence and in absence of water, in order to understand its role.

[ENG] Global warming, caused mostly by the increasing of greenhouse gas concentrations in the atmosphere, has became one of the most serious environmental concerns. Between the major greenhouse gases, carbon dioxide had the most significant increase. Its high availability, non-flammability, low toxicity and independency from the food supply chain, makes CO2 utilization as a carbon feedstock an important topic from both industrial and academic perspectives. The aim of this work was to develop process intensification strategies for cyclic carbonate production from CO2 and epoxides. Cyclic carbonates are versatile molecules which may become a future platform to introduce CO2 as a renewable carbon feedstock into the chemical sector. Indeed, cyclic carbonates find use in a wide range of applications as electrolytes for lithium batteries, polar aprotic solvents, pharmaceutical intermediates and also as monomers in polymer production. For the first time, zinc (II) complexes of arylhydrazones of β-diketones (AHBD) combined with ionic liquids were used as catalysts for the production of cyclic carbonates. Different cation and anion families were explored in order to understand the effect of specific functional groups on the final reaction yield and selectivity. Results confirmed the importance of the nucleophilicity of the anion, with halogens presenting the better results. Regarding the cation structure, it was possible to conclude that the bulkiness of the structure was the more important factor to have in consideration. Also the effects of pressure, temperature, type of solvent and catalyst concentration were studied and a high-pressure extraction process for an efficient product separation and recycling of the catalytic system was proposed. Finally, in the context of developing a green continuous flow process for CO2 conversion into cyclic carbonates, two different engineering approaches were investigated. On one hand a supported ionic liquid onto an alginate aerogel matrix was prepared, characterized and applied as catalytic system. On the other hand, a continuous flow process using a bulk ionic liquid phase as catalyst was carried out. Both processes allowed for cyclic carbonate production from a bio-based epoxide (limonene oxide) in the production of limonene carbonate, a 100% renewable cyclic carbonate. This thesis provides new opportunities for cyclic carbonate production from CO2 and epoxides in the context of sustainable processing.
[PT] O aquecimento global provocado principalmente pelo aumento das concentrações de gases de efeito estufa na atmosfera tornou-se numa das mais sérias preocupações em termos ambientais. Entre os principais gases responsáveis pelo efeito de estufa, temos o dióxido de carbono. Pelo facto de estar bastante disponível, de ser não inflamável, ter baixa toxicidade e devido a sua independência em relação a cadeia alimentar, o uso do CO2 como matéria-prima tem vindo a ganhar muita atenção quer do ponto de vista industrial e quer académico. O objetivo deste trabalho consiste no desenvolvimento de estratégias de intensificação do processo responsável pela produção de carbonatos cíclicos a partir da reação de epóxidos com CO2. Por sua vez, os carbonatos cíclicos produzidos tem várias aplicações, podem ser utilizados como eletrólitos nas baterias de lítio, como intermediários farmacêuticos e também como monómeros para a produção de polímeros. Pela primeira vez, complexos de zinco (II) de arilhidrazonas de -dicetonas combinados com líquidos iónicos foram utilizados como catalisadores na produção de carbonatos cíclicos. Diferentes famílias de aniões e catiões foram estudadas, com o objetivo de compreender o efeito destes grupos funcionais na selectividade e no rendimento final da reação. Os resultados confirmaram a importância da nucleofilicidade do anião, com os iões de halogénios a apresentar os melhores resultados. Preservando à estrutura de catião, foi possível concluir que o tamanho da estrutura era o fator mais importante a ter em consideração. O efeito da pressão, temperatura, tipo de solvente e catalisador foram alguns dos parâmetros estudados, adicionalmente um processo de extração a alta pressão foi proposto como forma eficiente de separação do produto final e reutilização do catalisador. Finalmente, com o objetivo de desenvolver uma tecnologia verde na conversão de CO2 em carbonatos cíclicos duas diferentes abordagens, em termos de engenharia, foram investigadas. Primeiro, foi preparado e devidamente caracterizado um catalisador suportado, composto por uma matriz de aerogéis de alginato, para posteriormente ser testado com sistema catalítico. Segundo, foi explorada a possibilidade de realizar esta reação em modo contínuo, utilizando com líquidos iónicos em “bulk” com catalisadores. Em ambos os processos foi possível a produção de carbonatos cíclicos a partir de um epóxido proveniente de recursos naturais (óxido de limoneno) produzindo assim carbonato de limoneno, um carbonato 100% bio-renovável. Esta tese fornece novas oportunidades para aumentar a produtividade do processo de produção de carbonatos cíclicos a partir do CO2.
Doctoral fellowship PD/BD/52497/2014, FCT/MEC (UID/QUI/50006/2013), ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265), project EXPL/QEQ-ERQ/2243/2013, project “Sun Storage – Harvesting and storage of solar energy”, reference POCI-01-0145-FEDER-016387, FCT (RECI/BBB-BQB/0230/2012) e AQUA-CO2NV ENE2014-53459-R.

Σκοπός της εργασίας αυτής είναι η ανάλυση του νέου νομικού καθεστώτος διαχείρισης και ελέγχου των χημικών ουσιών σε ευρωπαϊκό επίπεδο και η ανάδειξη των ποικίλων διακυβευμάτων που αυτό θέτει. Το νέο αυτό νομικό καθεστώς, παρά την μακροχρόνια διαβούλευση του, δεν είναι τελικά απαλλαγμένο από αδυναμίες και προβλήματα εφαρμογής. Πρόκειται για τον νέο κανονισμό REACH (αρχικά του Registration, Evaluation and Authorisation of Chemicals) ή κανονισμό 1907/2006/ΕΚ. Ο κανονισμός REACH αποτελεί ένα ενιαίο ευρωπαϊκό νομοθέτημα για την καταχώριση, την αξιολόγηση, την αδειοδότηση και τους περιορισμούς των χημικών ουσιών, αντικαθιστώντας 40 διαφορετικά υφιστάμενα νομοθετικά μέτρα. Η εργασία χωρίζεται στην εισαγωγή, σε έξι κεφάλαια και τέλος τα συμπεράσματα. Στην εισαγωγή παρουσιάζεται η υφιστάμενη νομοθεσία της ευρωπαϊκής ένωσης για τις χημικές ουσίες, τα προβλήματα από την εφαρμογή της καθώς και η ανάγκη για ένα νέο νομοθετικό πλαίσιο το οποίο θα αντικαταστήσει το υφιστάμενο και θα έχει ως πρωταρχικό σκοπό την προστασία της ανθρώπινης υγείας και του περιβάλλοντος. Αναφορά γίνεται στην βιώσιμη ανάπτυξη και την πράσινη χημεία, καθώς αποτελούν βασικούς πυλώνες του κανονισμού. Επίσης παρουσιάζονται οι βασικές αρχές του κανονισμού (αρχή της προφύλαξης, της υποκατάστασης κλπ) καθώς και οι επιδιωκόμενοι στόχοι από την εφαρμογή του. Στο πρώτο κεφάλαιο γίνεται μια αναλυτική παρουσίαση της αρχής της προφύλαξης, η οποία αποτελεί βασική και θεμελιώδης αρχή του κανονισμού. Γίνεται αναφορά στην σχέση της με την αρχή της πρόληψης, στην πορεία της μέσα στο ευρωπαϊκό δίκαιο και στη διατροφική πολιτική της ευρωπαϊκής ένωσης καθώς και η αντιμετώπισή της από το ελληνικό δικαιικό σύστημα. Στο δεύτερο κεφάλαιο παρουσιάζεται αναλυτικά η οικοδόμηση του κανονισμού REACH, μέσω των σημαντικότερων χρονολογικών γεγονότων που άλλοτε ενίσχυσαν και άλλοτε αποδυνάμωσαν το κανονισμό, ικανοποιώντας κάθε φορά και διαφορετικά συμφέροντα ή απαιτήσεις, έως την οριστικοποίηση του τελικού του κειμένου. Ειδική αναφορά γίνεται στο ρόλο του Παγκόσμιου Οργανισμού Εμπορίου για τη διαμόρφωση του τελικού κειμένου του κανονισμού. Στη συνέχεια, στο τρίτο κεφάλαιο, παρουσιάζονται αναλυτικά το πεδίο εφαρμογής του κανονισμού, τα θεσμικά όργανα και οι αρμοδιότητές τους καθώς και οι βασικές διατάξεις του κανονισμού, η καταχώριση, η αξιολόγηση, η αδειοδότηση και περιορισμοί των χημικών ουσιών. Ακολουθεί το τέταρτο κεφάλαιο, όπου παρουσιάζεται ο κανονισμός CLP (αρχικά του Classification, Labelling, Packaging) για την ταξινόμηση, την επισήμανση και συσκευασία χημικών ουσιών και μειγμάτων ή κανονισμός 1272/2008/EK. Ο κανονισμός CLP συμπληρώνει και τροποποιεί τον κανονισμό REACH στο κενό που παρουσιάζει όσον αφορά την ταξινόμηση, την σήμανση και τη συσκευασία των χημικών ουσιών και τον εναρμονίζει με το Παγκόσμιο Εναρμονισμένο Σύστημα ταξινόμησης και επισήμανσης για τις χημικές ουσίες και τα μείγματα των Ηνωμένων Εθνών. Στο πέμπτο κεφάλαιο γίνεται μια αναλυτική αποτίμηση του κανονισμού REACH, καθώς παρουσιάζονται και αναλύονται τόσο οι θετικές του όψεις όσο και οι αδυναμίες του. Αναλυτική αναφορά γίνεται στο κόστος εφαρμογής του κανονισμού καθώς και στα οικονομικά οφέλη που προκύπτουν από την εφαρμογή του. Επίσης παρουσιάζοντα τα προβλήματα ερμηνείας και εφαρμογής του κανονισμού. Ακολουθεί το έκτο κεφάλαιο, στο οποίο γίνεται αναφορά στην εφαρμογή του κανονισμού REACH στην Ελλάδα καθώς παρουσιάζεται η υπεύθυνη αρμόδια αρχή για την εφαρμογή του κανονισμού και ο ρόλος της, το πεδίο εφαρμογής του κανονισμού (επιχειρήσεις χημικών προϊόντων) καθώς και ο ρόλος του Συνδέσμου Ελληνικών Χημικών Βιομηχανιών. Τέλος στα συμπεράσματα γίνεται μια συγκεντρωτική παρουσίαση και σύγκριση των αρνητικών και θετικών χαρακτηριστικών του κανονισμού και αποτιμάται ο βαθμός της επίτευξης των αρχικών στόχων του μέσα στο χρονικό διάστημα από την ημερομηνία εφαρμογής του έως σήμερα. Επίσης παρουσιάζεται πως ο κανονισμός REACH αποτελεί καινοτόμο νομοθετικό εργαλείο στα χέρια της διοίκησης αν και αποδυναμωμένος σε σχέση με το αρχικό του κείμενο και την αρχική πεποίθηση για ολοκληρωμένη και υψηλού επιπέδου προστασία της ανθρώπινης υγείας και του περιβάλλοντος.
Aim of this work is the analysis of new legal regime of management and control of chemical substances in European level and the emergence of diverse implications that this poses. This new legal regime, despite its long-lasting consultation, is not finally exempted from weaknesses and problems of application. This is the new REACH Regulation (initials of the Registration, Evaluation and Authorisation of Chemicals) or regulation 1907/2006/EC. REACH is a uniform European legislation on the registration, evaluation, authorisation and restriction of chemicals, replacing 40 different existing legislative measures. The work is divided into the introduction, six chapters and finally conclusions. The introduction presents the existing EU legislation on chemicals, the problems of implementation as well as the need for a new legal framework which will replace the existing and will have as fundamental aim the protection of human health and environment. Reference is made to sustainable development and green chemistry, which are key pillars of the regulation. It also presents the basic principles of the regulation (precautionary principle, substitution principle, etc) as well as the objectives pursued by its application. In the first chapter becomes an analytic presentation of precaution principle, which constitutes basic and fundamental principle of regulation. Reference is made in relation to the prevention principle, in European law and food policy in the European Union as well as its confrontation from Greek law system. In the second chapter is presented in detail the construction of REACH regulation, by means of the most important chronological facts that sometimes reinforced and sometimes watered down regulation, satisfying each time and different interests or requirements, until the finalization of the final text. Special reference to the role of the World Trade Organization is made for the configuration of final text of regulation. Afterwards, in the third chapter, are presented in detail the field of application of regulation, the institutional bodies and their competences as well as the basic provisions of regulation, the registration, evaluation, authorisation and restriction of chemicals. Fourth chapter follows, where regulation CLP is presented (initials of the Classification, Labeling and Packaging) for the classification, labeling and packaging of substances and mixtures or regulation 1272/2008/EC. Regulation CLP supplements and modifies regulation REACH in the void that it presents with regard to the classification, labeling and packing of chemical substances and it harmonizes REACH with the World Harmonized System of classification and labeling for the chemical substances and mixtures of United Nations. In the fifth chapter becomes an analytic assessment of regulation REACH, while are presented and analyzed both positive aspects and weaknesses. A detailed reference becomes in the cost of implementing the regulation and to the economic benefits arising from its application. Also the problems in the interpretation and application of the regulation are presented. Following the sixth chapter, in which reference is made in the implementation of reach in Greece as the responsible authority for the application of the regulation and its role, the field of application of regulation (enterprises of chemical products) as well as the role of the Association of Greek Chemical Industries. Finally, in the conclusions is a summary and comparison of negative and positive characteristics of regulation and evaluation of the extent of the initial objectives within the period from the date of application until now. It also shows that REACH is an innovative legislative tool in the hands of the administration, although weak compared to the initial text, and the initial conviction for integrated and high level of protection of human health and environment.