The present study aims to develop a luminescent epoxy coating with low interfacial interaction to paraffinic oils and with a lower incidence of voids or bubbles. The proposed development of the coating occurred from an epoxy resin widely used as a coating of pipes for the oil industry. Initially it was added to the epoxy a modifying agent, causing the Epoxy-M, causing the Epoxy-M, which has higher thermal stability, lower interfacial interaction and lower the incidence of bubbles that the Epoxy. After selecting a pigment that meet requirements such as organic nature, good compatibility with epoxy, the fluorescence emission with excitation out of UV, good cost/benefit, it was added to polymer systems. Later heat treatments were performed between 60 and 120°C for periods between ¼ and 6 ho urs, followed by determining the rate of cure, luminescent analysis, interfacial characterization with oil and finally the evaluation of the formation of bubbles. The results show that Heat treatments at lower temperatures for longer periods are shown to be most suitable for the cure of both the systems polymeric, where it is possible to obtain better response photoluminescent and greater rate of crosslinking. / O presente estudo tem por finalidade desenvolver um revestimento epoxídico luminescente com baixa interação interfacial a óleos parafínicos e com menor incidência de vazios ou bolhas. O desenvolvimento do revestimento proposto se deu a partir de uma resina epoxídica amplamente utilizada como revestimento de dutos pela indústria do petróleo. Inicialmente foi adicionado ao Epóxi, um agente modificante, originando o Epóxi-M, que possui maior estabilidade térmica, menor interação interfacial e menor a incidência de bolhas que o Epóxi. Após selecionar um pigmento que atendesse requisitos como natureza orgânica, boa compatibilidade com epóxi, emissão fluorescente com excitação fora do UV, bom custo/benefício, foi adicionado aos sistemas poliméricos. Posteriormente foram realizados tratamentos térmicos entre 60 e 120ºC por períodos entre ¼ e 6 horas, seguidos da determinação do grau de cura, análises luminescentes, caracterização interfacial com o petróleo e por fim a avaliação da formação de bolhas. Os resultados mostram que tratamentos térmicos em temperaturas mais baixas por períodos mais longos demonstram ser mais adequados para os dois sistemas poliméricos, onde é possivel obter melhor resposta fotoluminescênte e maior grau de reticulação.

Dans le vin, les amines biogènes sont essentiellement d'origine microbienne, et sont produitesnotamment par les bactéries lactiques Oenococcus oeni, principal agent responsable de lafermentation malolactique, possède de nombreuses auxotrophies vis-à-vis des acides aminés.Aucune étude n'a été menée sur la relation entre l’auxotrophie vis-à-vis d’un acide aminé et leniveau de l’amine correspondante. 80 souches de Oenococcus oeni ont été isolées de vinsrouges. Leurs auxotrophies vis-à-vis d’acides aminés précurseurs d’amines biogènes (Arg,Tyr, His et Phe) ainsi que la présence de gènes codant des enzymes impliquées dans lasynthèse des amines ont été étudiées. Aucune relation entre auxotrophie et niveau deproduction d’amines ne peut être établie pour les souches testées. La présence de gènes codantdes enzymes impliquées dans la synthèse d’amines n’est pas non plus corrélée avec laproduction effective d’amines. Nous montrons pour la première fois que Oenococcus oeni estun producteur d’agmatine. Cette production est étroitement liée à la souche bactérienne. Lasouche la plus adaptée au milieu acide est celle qui consomme le plus l’arginine et enproportions équivalentes par les 2 voies : voie de l’arginine déiminase et voie de l’argininedécarboxylase. L’effet d’une addition d’agmatine dans des vins montre une atténuation del’effet boisé du Chardonnay sans doute par formation de base de Schiff ente les composésd’arôme et cette amine / In wine biogenic amines (BA) are mainly of microbial origin, Oenococcus oeni, the mainresponsible for malolactic fermentation, has been identified as a BA producer from nitrogenprecursors. Oenococcus oeni possess numerous amino acid auxotrophies that are precursors ofbiogenic amines. No study has been done so far to look at the relationship betweenauxotrophy for amino acids precursors of BA and the level of BA in the medium. In order todo so, 80 Oenococcus oeni strains were isolated from red wines. The detection of genesencoding the different decarboxylases responsible for BA synthesis has been realised. Inparallel, the auxotrophy for the four amino acids (Arg, Tyr, His, Phe) precursors of BA hascharacterized. Our results demonstrate that there is not direct correlation between auxotrophyand the accumulation of the corresponding BA as well as between the presence ofdecarboxylase gene and the accumulation of the corresponding BA. High levels of agmatineproduced from arginine decarboxylation by Oenococcus oeni is reported for the first time.Agmatine production is strain dependant. the most adapted to acidic environment is the strainwhith use arginine in higher level with same proportion for ADI pathway and argininedecarboxylase. Agmatine addition in wines reduce woody aroma probably by formation ofsciff bases between aromla compounds and amine

Water-in-oil (w/o) microemulsion systems, stabilised by either an anionic surfactant or a cationic surfactant were studied. The anionic system consisted of ethoxylated nonylphenol phosphate esters (Atpol), Shellsol oil and an alcohol. These microemulsions tolerated an increase in ionic strength of the water phase up to a point: Beyond this point no microemulsion could be obtained. However, adding amine salts, e.g. diethanolamine nitrite, improved the emulsification of the aqueous phase. Increasing the alcohol (cosurfactant) chain length up to octanol also increased the uptake of the aqueous phase. Thus octanol yielded the best results in terms of emulsifying large volumes of the water-phase, particularly at high salt concentrations. A key objective was to prepare stable microemulsions with high nitrite content. The maximum microemulsion nitrite contents (expressed as NaNO2equivalent by mass) achieved were: -- About 10% when a 30% NaNO2solution was emulsified -- 23% when neat diethyl ethanolamine nitrite (DEEAN) was solubilized, and -- 23% for mixtures of diethanolamine nitrite (DEtOHAN) and NaNO2 in water. The cationic microemulsion system was based on the double-chain cationic surfactant, didodecyldimethyl ammonium chloride (DDAC). In this case the solubilization of the following acetate salts were investigated: ammonium, sodium, magnesium, zinc and manganese. As with the Atpol system, it was found that increasing the ionic strength is detrimental to microemulsification of the aqueous phase. In the DDAC system, an increase in the alcohol chain length beyond butanol led to reduced aqueous phase uptake. Thus the natures and concentrations of the surfactant and the cosurfactant as well as the ionic strength of the aqueous phase determine the stability and the emulsification of large volumes of aqueous phase. In general there is an optimum ionic strength at which the salt content of the microemulsion formulation is maximised. / Dissertation (MSc (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

The objective of this work was to evaluate the fundamentals of the currently available CO2 separation technologies and provide a solution for the efficient capture of carbon dioxide from various point source emitting industries. In order to realize a robust approach to advancing the solution to this global issue, the versatility of the process to the range of compounds contained within the stream(s) to be processed must be maintained. It is clear that adsorption, membrane, and aqueous amine based processes are all capable. However, only aqueous amine scrubbing appears economically viable at the current stage of development. In order to challenge this, and potentially drive the separation costs lower, this work centered on hybridizing aqueous amine chemistry and dry adsorption based separations to produce a novel nano-porous material capable of efficient removal of CO2 from flue gas (5% CO2 balance N2 with moisture). In order to combine aqueous amine scrubbing with dry adsorption, a few approaches were considered and evaluated. These included, amine impregnation within the vast pore volume of PE-MCM-41, surface grafting of various amino silane compounds, and finally, a novel approach of volume based amine functionalization (3D grafting). Application of pore-expanded MCM-41 (PE-MCM-41) mesoporous silica coated with 3-[2-(2-aminoethyl-amino)ethylamino]propyltrimethoxysilane (TRI) has been extensively examined for the adsorption of CO2 from N2. A systematic study of the amine loading as a function of the relative amounts of TRI and water used during the grafting procedure, and the temperature of the grafting reaction was carried out. Extremely high levels of active amine content were achieved using prehydrated silica surfaces at grafting temperatures below reflux in order to facilitate thermally controlled water-aided surface polymerization of the aminosilanes. Abstract iii The CO2 adsorption capacities and rates were determined for all materials as a function of the amount of TRI and water per gram of support added to the grafting mixture. The optimal TRI grafted PE-MCM-41 adsorbent exhibited a 2.65 mmol/g adsorption capacity at 25 °C and 1.0 atm for a dry 5% CO2 in N2 feed mixture, which exceeded all literature reported values, for both meso- and microporous materials under the conditions used in this study. Further, the apparent adsorption and desorption rates with the amine functionalized materials were exceedingly high. When considering the grafted amine quantity, the adsorption capacity and rate were found to be mutually dependent on each other, exhibiting an apparent optimal combination. In comparison to zeolite 13X, the optimally loaded TRI-PE-MCM-41 was far superior in terms of dynamic adsorption and desorption performance. These results were further enhanced when the adsorbents were challenged with a humid stream of 5% CO2/N2. The TRIPE-MCM-41 exhibited a 10% increase in CO2 adsorption capacity, whereas the 13X zeolite did not retain any significant CO2 adsorption capacity. The novel concept of an internally variably staged permeator was introduced. A theoretical model was developed and used as the basis for simulation studies. The advantage of the internal variably staged design was shown to permit a very high extent of separation similar to a two stage permeator for purity, while maintaining similar flux rates as per a single stage permeator. This IVSP concept has also taken existing membrane materials and mechanically translated their process performance to a higher level. As such, the unit should prove effective for front end process stream cleanup requirements prior to an adsorption process with the novel TRI-PE-MCM-41 nano-porous adsorbent.

A series of para-substituted phenylethylamine analogues bound to the enzyme aromatic amine dehydrogenase have been simulated using quantum mechanical electronic structure calculations and molecular mechanical molecular dynamics simulations. Trends have been verified connecting bond dissociation energy (and thus driving force) to observed rate constants and activation enthalpy. Trends have been identified in connecting statistics drawn from molecular dynamics simulations and the temperature dependence of the kinetic isotope effect, notably that as the temperature dependence of the kinetic isotope effect increases the flexibility of the promoting vibration decreases. This is explained as being more effected by thermal energy put into the system, and therefore more affected by temperature.

The use of enzymes, nature´s own catalysts, both isolated or as whole cells to perform chemical transformations is called biocatalysis. As a complement to classical chemical catalysis, biocatalysis can be an environmentally friendly and more economical option in the production and synthesis of chemicals. Research on the application of amine transaminases in synthesis of chiral amines have exploded over the last two decades and interest from the industry is increasing. Amine transaminases are promising catalysts due to their ability to perform reductive amination of ketones with excellent enantioselectivity. For a process to be efficient, high substrate specificity of the applied enzyme is an important factor. A variant of Chromobacterium violaceum amine transaminase that was obtained through rational design has an increased specific activity toward (S)-1-phenylethylamine and a set of 4´-substituted acetophenones. This result makes this variant a promising catalyst for the asymmetric synthesis of similar amines. Amine transaminase catalyzed asymmetric synthesis of amines generally suffers from unfavorable equilibrium. Two methods that include spontaneous tautomerization and biocatalytic amidation for equilibrium displacement have therefore been developed. Efficient assays and screening methods are demanded for the discovery and development of novel amine transaminases. For this purpose, a sensitive fluorescence-based assay that holds promise as a high-throughput screening method was developed. One of the major obstacles for application of enzymes in industrial processes is the instability of the enzyme toward harsh conditions. The stability of Chromobacterium violaceum amine transaminase was investigated and improved using co-solvents and other additives. Co-lyophilization with surfactants was also applied to improve the performance of the same enzyme in organic solvents. / <p>QC 20161017</p>

Condensation of 2,3-dichloromaleic anhydride and o-phenylenediamine in refluxing toluene affords the three compounds 2,3-dichloro-N-o-C6H4(NH2)maleimide (1), N,N¢-o-C6H4-bis(2,3-dichloromaleimide) (2), and 2,3-dichloropyrrolo[1,2-a]benzimidazol-1-one (3), with compound 1 as the major product. Repeating the same reaction in the presence of added PTSA furnishes compound 3 as the major product. Treatment of 3 with methylthiol in the presence of pyridine affords monosulfide compounds 2-chloro-3-methylthiopyrrolo[1,2-a]benzimidazol-1-one (4) and and the disulfide derivatives 2,3-di(methylthio)pyrrolo[1,2-a]benzimidazol-1-one (5). The substitution of the first chlorine group in compound 3 occurs regioselectively at C-3 to produce compound 4, followed by replacement of the remaining chlorine group to furnish the disulfide compounds 5. The new compounds 1-5 have been isolated by column chromatography and characterized by IR, NMR, XRD, CV and etc.

Thesis (MSc. (Chemistry)) -- University of Limpopo, 2016 / 2-Benzenesulfonyloxyquinoxaline was prepared following literature procedure followed by palladium-catalysed Negishi coupling reactions to yield the corresponding, 2-mono-substituted quinoxaline derivatives, 2-phenylquinoxaline and 2-butylquinoxaline. These Negishi cross-coupled derivatives were treated with various nucleophiles, in tetrahydrofuran at room temperature, to yield a series of di-substituted quinoxaline derivatives containing; aryl-, heteroaryl-, arylalkynyl- and alkyl-substituents. Tri-substitution was successful with reaction of 6-chloro-2-benzenesulfonyloxyquinoxaline with excess phenyl-magnesium bromide to yield 2,3,6-triphenylquinoxaline. Sonogashira cross-coupled compounds were successfully synthesised by reacting 2-benzenesulfonyloxyquinoxaline, 6-nitro-2-benzenesulfonyloxyquinoxaline and 6-chloro-2-benzenesulfonyloxyquinoxaline using phenylacetylene, respectively. Nucleophilic substitution was only successful on 2-(2-phenylethynyl)quinoxaline to yield 3-butyl-2-(2-phenylethynyl)quinoxaline. The formation of carbon-nitrogen bonds was accomplished via palladium-catalysed Buchwald-Hartwig amination of 2-benzenesulfonyloxyquinoxaline with arylamines to afford N-phenylquinoxalin-2-amine and N-benzylquinoxalin-2-amine in good to high yields. N-phenylquinoxalin-2-amine was subsequently treated with iodomethane to synthesise N-methyl-N-phenylquinoxalin-2-amine. Nucleophilic substitution on Buchwald-Hartwig coupled compounds was only successful when using alkyl nucleophiles. The reaction of all these quinoxaline derivatives with various nucleophiles does not stop at the stage of α-adduct formation, but continues with the oxidation of these compounds to aromatic substitution products. All synthesised compounds were characterised by NMR, and mass spectral data as well as melting points where applicable. N-Methyl-N-phenylquinoxalin-2-amine and 2,3,6-triphenylquinoxaline showed percentage parasite viability of 42.64% and 58.12%, respectively, against the Plasmodium falciparum strain 3D7. N-Methyl-N-phenylquinoxalin-2-amine showed MIC90 of 16.4 and MIC99 of 19 μM, while 6-chloro-2-(2-phenylethynyl)quinoxalin showed MIC90 of 8.15 and MIC99 of 9.26 μM values against Mycobacterium tuberculosis (Mtb)-H37Rv strains.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23036号 / 理博第4713号 / 新制||理||1675(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)准教授 加納 太一, 教授 時任 宣博, 教授 依光 英樹 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

The diploma thesis describes the influence of humid conditions on the curing of epoxy resins by multifunctional amines. The aim of the experimental part was the identification of degradation products and their quantification, as well as the determination of the influence of humid conditions on the degree of hardening, modulus of elasticity, and flexural strength. Another goal was to optimize the formulation of the reactive mixture for the preparation of epoxy resin with lower susceptibility to carbamate bloom. The degradation products were evaluated by determining the mechanical properties by bending test according to the standard ČSN EN 179-1. The degree of hardening was monitored through temperature modulated differential scanning calorimetry (TMDSC). Degradation products were identified by Fourier transform infrared spectroscopy (FTIR) and quantified by UV-VIS spectroscopy. The morphology of the surface layer was monitored by confocal laser scanning microscopy (CLSM). The dependence of the relative humidity of the environment on the curing process of the epoxy resin and its resulting mechanical properties was determined. Based on the analyzes, a modification of the formulation for the suppression of spurious carbamate during the curing of the epoxy matrix was designed and experimentally verified.