Dissertations / Theses on the topic 'Cosolvency'

A creosote treatment facility was active during the 1950’s and 1960’s at a railroad tie yard site. In 1990, creosote contamination was discovered along a creek bank at the site. Phytoremediation was selected as the remedial technology and hybrid poplar trees were planted at the site in 1997. A research project was designed to: 1) characterize the site through collection of soil and ground water samples; 2) assess phytoremediation effects of 3 grasses, clover, fescue and rye, in creosote-contaminated surface soils; 3) perform assessment of the hybrid poplar tree phytoremediation system; 4) develop a hybrid poplar tree evapotranspiration model. This thesis is focused on the first and second items on the research agenda. Soil and ground water samples were collected and analyzed for 6 polycyclic aromatic hydrocarbons (PAHs), acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene. Site characterization revealed multiple creosote sources. Areal subsurface bedrock DNAPL distribution, approximately 6500 ft², was much greater than previously reported. Total PAHs (Σ 6 PAHs) in the soil and ground water ranged from below detection limits (BDL) to 8,276 mg/kg and BDL to 1.58 mg/L, respectively. Aqueous phase PAHs should be available for hybrid poplar tree and microbial uptake. Dissolution and diffusion of PAH constituents from the free product phase to the aqueous and soil phases contaminated both matrices. PAH cosolvency effects were also evident. The presence of more soluble PAHs in the aqueous phase enhanced the solubility of two hydrophobic PAHs, chrysene and benzo(b)fluoranthene. Phytoremediation effects of fescue, rye, and clover grasses were assessed in creosote-contaminated surface soils. Over the 9 month period, clover grass growth was very poor. Clover data was not used in comparative analyses. Rye and fescue grasses exhibited acceptable growth. In planted and control (unplanted-amended) plots, acenaphthene, fluorene, phenanthrene, fluoranthene, and pyrene soil concentrations were reduced 72, 50, 73, 55 and 49 percent, respectively. Chrysene reduction was not statistically significant. During the first 4 months of the study, dry site conditions limited grass growth and subsurface biological activity. The site received approximately 16 inches of precipitation during the last 3 months of the study, including multiple, intense precipitation events. The subsurface was saturated for prolonged periods of time and oxygen transfer to indigenous microorganisms was likely limited. The root structures of fescue and rye grasses were neither dense nor complex enough to promote phytoremediation effects. PAH reductions were generally greater for constituents with higher aqueous solubilities. It is thought that PAH losses were primarily due to solubilization and/or microbial uptake.
Master of Science

COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Neste trabalho foi desenvolvido um programa para simulação numérica do fluxo bifásico em meios porosos com transferência de massa entre as duas fases e transporte dos solutos em cada fase. O programa calcula o aumento da mobilidade da fase não aquosa e da solubilidade de seus componentes na água como resultado da adição de um co- solvente. O objetivo foi simular problemas de contaminação no subsolo com líquidos imiscíveis com a água e a remediação através da técnica de injeção de co-solventes, assim como a contaminação a partir de vazamentos de gasolina acrescida de álcool em postos de abastecimento. Podem-se ainda resolver problemas de fluxo bifásico envolvendo uma fase gasosa. Foi desenvolvido e implementado um modelo para a transferência de massa durante o fluxo das duas fases. O cálculo das propriedades das duas fases ao longo do tempo é feito utilizando o diagrama ternário de fases. Para resolver as equações do fluxo e do transporte de solutos foi empregado o método de elementos finitos.
A computer code was developed for numerical simulation of two-phase flow in porous media considering mass transfer between the phases involved and solute transport in each phase. Enhanced mobility of nonaqueous phase and enhanced aqueous solubility of its components as a result of cosolvent injection are calculated. The objective of this work was to simulate subsurface contamination by nonaqueous phase liquids and remediation utilizing cosolvent injection technique, and also contamination by gasoline with alcohol from fuel tanks. It is also possible to solve two-phase flow problems involving a gaseous phase. A model for mass transfer during two-phase flow was developed and implemented. Properties variation with time for both phases is calculated using ternary phase diagram. Finite element method was used to solve flow and solute transport equations.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The benznidazole (BNZ) is the only alternative for Chagas disease treatment in Brazil. This drug has low solubility, which restricts its dissolution rate. Thus, the present work aimed to study the BNZ interactions in binary systems with beta cyclodextrin (?-CD) and hydroxypropyl-beta cyclodextrin (HP-?-CD), in order to increase the apparent aqueous solubility of drug. The influence of seven hydrophilic polymers, triethanolamine (TEA) and 1-methyl-2- pyrrolidone (NMP) in benznidazole apparent aqueous solubility, as well as the formation of inclusion complexes was also investigated. The interactions in solution were predicted and investigated using phase solubility diagram methodology, nuclear magnetic resonance of protons (RMN) and molecular modeling. Complexes were obtained in solid phase by spray drying and physicochemical characterization included the UV-Vis spectrophotometric spectroscopy in the infrared region, scanning electron microscopy, X-ray diffraction and dissolution drug test from the different systems. The increment on apparent aqueous solubility of drug was achieved with a linear type (AL) in presence of both cyclodextrins at different pH values. The hydrophilic polymers and 1-methyl-2-pyrrolidone contributes to the formation of inclusion complexes, while the triethanolamine decreased the complex stability constant (Kc). The log-linear model applied for solubility diagrams revealed that both triethanolamine and 1-methyl-2-pyrrolidone showed an action cosolvent (both solvents) and complexing (1-methyl-2-pyrrolidone). The best results were obtained with complexes involving 1-methyl-2-pyrrolidone and hydroxypropylbeta- cyclodextrin, with an increased of benznidazole solubility in 27.9 and 9.4 times, respectively. The complexes effectiveness was proven by dissolution tests, in which the ternary complexes and physical mixtures involving 1-methyl- 2-pyrrolidone and both cyclodextrins investigated showed better results, showing the potential use as novel pharmaceutical ingredient, that leads to increased benznidazole bioavailability
A doen?a de Chagas tem como ?nica alternativa para tratamento, no Brasil, o benznidazol (BNZ). Este f?rmaco possui baixa solubilidade, o que restringe sua velocidade de dissolu??o. Diante disto, o presente trabalho teve como objetivo o estudo das intera??es do BNZ em sistemas bin?rios com a beta-ciclodextrina (?-CD) e a hidroxipropil-beta-ciclodextrina (HP-?-CD), com o intuito de aumentar a solubilidade aquosa do f?rmaco. A influ?ncia de sete pol?meros hidrof?licos, da trietanolamina (TEA) e da metil-1-pirrolidona-2 (NMP) na solubilidade aquosa aparente do benznidazol, assim como na forma??o dos complexos de inclus?o, tamb?m foi investigada. As intera??es em solu??o foram previstas e investigadas usando os diagramas de solubilidade de fases, espectroscopia de ressonancia magn?tica nuclear de pr?tons (RMN) e modelagem molecular. Diferentes complexos foram obtidos em fase s?lida por secagem por atomiza??o em aparelho de spray dryer e a caracteriza??o f?sico-qu?mica destes incluiu a espectrofotometria UV-Vis, a espectroscopia na regi?o do infravermelho, a microscopia eletr?nica de varredura, a difra??o de raios-X e os ensaios de dissolu??o do f?rmaco a partir das diferentes amostras. O aumento da solubilidade aquosa aparente do f?rmaco foi alcan?ada de forma linear (perfil AL) na presen?a de ambas as ciclodextrinas em diferentes valores de pH. A presen?a dos pol?meros hidrof?licos e da metil-1-pirrolidona-2 contribui para a estabiliza??o dos complexos formados, enquanto a trietanolamina diminuiu a constante de estabilidade (Kc) dos complexos formados. O modelo do log linear aplicado aos diagramas de solubilidade revelou que a trietanolamina e a metil-1-pirrolidona-2 mostraram uma a??o cossolvente (ambos solventes) e complexante (metil-1-pirrolidona-2). Os melhores resultados foram obtidos com os complexos envolvendo a metil-1-pirrolidona-2 e a hidroxipropil-beta-ciclodextrina, com um aumento de solubilidade do f?rmaco em 27,9 e 9,4 vezes, respectivamente. A efic?cia dos complexos foi comprovada pelos ensaios de dissolu??o, nos quais os complexos tern?rios e misturas f?sicas envolvendo a metil-1-pirrolidona-2 e as ciclodextrinas investigadas apresentaram os melhores resultados, demonstrando a possibilidade de uso como um novo insumo farmac?utico, que leve ao aumento da biodisponibilidade do benznidazol
2020-01-01

Diese Dissertation beschäftigt sich mit der passiven Probenahme von hydrophoben organischen Schadstoffen in Oberflächengewässern: Polyaromatische Kohlenwasserstoffe (PAK), polychlorierte Biphenyle (PCB), polybromierte Biphenylether (PBDE), Organochlorpestizide (u. a. HCH, DDX) und weitere hydrophobe Pestizide. Die Zielstellung dieser Arbeit lag bei der Validierung des Silikonstabs als Alternativmethode im Gewässermonitoring zu konventionellen Probenahmetechniken wie Schöpf- und Wochenmischproben der Wasserphase sowie Schwebstoffanalysen. Die Probenahme mit dem Silikonstab erfolgte durch dessen Exposition im Gewässer für einen Zeitraum zwischen einer Woche und mehreren Monaten. Nach Einholung wurden die im Silikonstab akkumulierten Schadstoffe (Analyten) mittels instrumenteller Analytik quantifiziert. Die Probenaufgabe erfolgte ohne vorherige Lösungsmittelextraktion durch direktes Erhitzen des Silikonstabs, wodurch die Analyten vom Polymer desorbieren (Thermodesorption). Die durch Hitze freigesetzten Analyten wurden direkt auf eine chromatographische Trennsäule gegeben und massenspektroskopisch quantifiziert. Nach Erhalt der Ergebnisse der Silikonstab-Analytik gibt es verschiedene Herangehensweisen für die Berechnung der zeitgemittelten Analytkonzentrationen im Gewässer, die in dieser Arbeit vorgestellt und diskutiert werden. Dazu gehören die Verwendung von experimentellen Daten aus Kalibrierversuchen und Berechnungen auf Grundlage von physikochemischen Eigenschaften der Analyten wie dem Sammler-Wasser-Verteilungskoeffizienten. Im Zuge dieser Arbeit wurde die Aufnahmekinetik des Silikonstabs bei verschiedenen Temperaturen und Fließgeschwindigkeiten mit Hilfe von Kalibrierversuchen untersucht. Die gewonnenen experimentellen Daten wurden für die Entwicklung von Rechenmodellen herangezogen, mit denen das Aufnahmeverhalten vorgesagt werden soll. Es wurden Sammler-Wasser-Verteilungskoeffizienten für den Silikonstab u. a. mit der Kosolvenzmethode bestimmt und als Parameter für die Berechnung von zeitgemittelten Analytkonzentrationen des Gewässers verwendet. Für die Validierung wurde der Silikonstab in zwei Gewässergütemessstationen der Fließgewässer Mulde (Dessau) und Elbe (Magdeburg) in Durchflussbehältern exponiert und die zeitgemittelten Analytkonzentrationen mit verschiedenen Rechenmodellen bestimmt. Die erhaltenen Werte werden mit gleichzeitig entnommenen Wochenmischproben der Wasserphase sowie monatlichen Schwebstoffproben verglichen und die Eignung des Silikonstabs als alternative Probenahmemethode für das Umweltmonitoring von Oberflächengewässern diskutiert.

Eptifibatide is a potent and highly specific inhibitor of platelet receptor glycoprotein IIb/IIIa and is indicated in the treatment of acute coronary syndrome. The commercial product Integrilin® (eptifibatide) Injection requires a cold/refrigerator storage condition. In an effort to improve the drug stability for room temperature storage and transportation, this study proposed a semi-aqueous formulation that contains 2 mg/ml dose, 10% ethanol, 40% propylene glycol and 50% 0.025 M citrate buffer. A carefully designed stability study was conducted in the pH range 4.25-6.25 under accelerated temperatures: 48°C, 60°C, 72.5°C. The results indicate that the proposed semi-aqueous vehicles greatly increased eptifibatide stability in comparison with aqueous vehicles. The pH-rate profiles of eptifibatide are V-shaped with the curves for semi-aqueous vehicles lower all over the test pH range. The pH of drug maximum stability is 5.25 in the aqueous vehicle, and it is shifted to 5.75 in the semi-aqueous vehicle. Studies indicate that eptifibatide degradation may involve a few different mechanisms: the specific acid catalyzed hydrolysis which is dominant in the acidic region, and a pH-dependent oxidation which is likely to be dominant in the basic region of the test pH range. The predicted drug shelf-life T90 at 25°C shows that an almost 2-fold increase can be achieved by formulating eptifibatide in the semi-aqueous vehicle, which is 60 months at its maximum stability pH 5.75 as opposed to the 33 months in the aqueous vehicle at its maximum stability pH 5.25.

Neurophysins (NPs) make up a relatively small, stable, and highly soluble class of proteins. They have physiological roles of storage and stabilizing' of peptide hormones oxytocin and vasopression within the posterior pituitary neurosecretory granules. At the concentration of NP found within the granules, NP would exist as a dimer in the absence or presence of bound peptide. The NP monomer-monomer interface involves B-sheet/ B-sheet contact, which can be modulated by the presence of cosolvent. This remarkable feature of NP makes it a model for Alzheimer's disease. One of the characteristics of Alzheimer's disease is the presence of plaques of B-amyloid protein that are deposited on the brain. The plaques are rich in B-structure. Being water-insoluble makes them impossible to be directly studied by solution-state NMR. The purpose of this study was to modify the solvent system to lower the NP dimerization constant and characterize the nature of solvent on dissociation of dimer. A set of cosolvents was selected to try to reduce NP dimerization at relatively high concentration of NP. The organic cosolvents included deuterated methanol, dimethyl sulfoxide, ethyl acetate, propionitrile, and acetonitrile. Also, the protein unfolding reagents, deuterated urea and guanidine monohydrochloride, were tried. The interaction between bromophenol blue and NP was also studied because this dye binds predominately to the dimer form of NP. Highresolution NMR techniques were used to sense the NP-I dimer I monomer equilibrium. Among the organic cosolvents used, only acetonitrile and propionitrile were found shift the dimer ~ monomer equilibrium significantly toward monomer. The cosolvent probably changed the character of the solvent system, penetrated the monomer-monomer interface and interacted with the interface residues, caused the break up of dimer. The unfolding reagents were found to partly unfold the NP simultaneously with dissociation of the dimer. Bromophenol blue binds to NP-I at low pH, but the solubility of NP-dye complex is too low to be studied extensively by solution-state NMR methods.

Formulation is a complex science. Many functional molecules require formulation to enhance their aqueous solubility or to promote and protect their function. Understanding the interaction between the formulation components is a necessary first step in that process. This project focuses predominantly on quantifying the interactions (synergistic and antagonistic) that arise when a triblock copolymer Pluronic (PI23) is mixed with the anionic surfactant sodium dodecyl sulfate (SDS), in the presence of the cosolvent, ethanol. The interaction between PI23 and SDS is synergistic, and leads to the formation of mixed micelles at low PI23 concentrations and liquid crystalline phases at high PI23 concentrations. Ethanol is shown to weaken that interaction, introducing antagonistic interactions at low PI23 concentrations. Moreover, we also study the physicochemical characteristics of some new biocompatible responsive polymers with potential biomedical applications. Here, the "formulation" is inherently built into the structure of the polymer-protein construct. These constructs possess a thermo-responsive character, and pulsed-gradient spin- echo NMR (PGSE-NMR) and small-angle neutron scattering (SANS) have been used to examine the solution conformation of these polymers as a function of temperature.

Systems in which there are strong specific interactions between the polymer and CO₂ are of interest in a number of applications including polymer foaming, coating and impregnation. Unfortunately, experimental data on the phase behavior of such systems are relatively scarce, as are models that explicitly consider specific interactions in such systems. The overall goal of this work was therefore to develop a method for the measurement of specific interactions in polymer + CO₂ systems and to apply such measurements to the development of a thermodynamic model for polymer solutions. This work demonstrates that in situ ATR-FTIR spectroscopy may be used to quantify specific interactions in CO₂ + polymer- systems that incorporate carbonyl, ether, siloxane and sulfone groups. However, carbonyl stretching frequencies cannot be used to quantify such interactions between CO₂ and carbonyl polymers, contrary to what has been suggested in the literature. This is because blue shifts in the carbonyl stretching frequencies were observed in the ATR-FTIR spectra of CO₂ + PVAc, CO₂ + PMMA, CO₂ + PLA, and CO₂ + PLGA85 systems. These CO₂ induced blue shifts can be attributed to dielectric effects, and therefore cannot be used to quantify specific interactions in these systems. We propose the use of the temperature dependence of the CO₂ bending mode to quantify specific interactions in CO₂ + carbonyl polymers. With this method, the enthalpies of association for C=O...CO₂ specific interactions were found to be between -7 and -10 kJ/mol in the order: CO₂ + PVAc > CO₂ + PCL ≈ CO₂ + PLA > CO₂ + PLGA85 > CO₂ + PMMA. The method was also extended to other CO₂ philic polymers, leading to enthalpies of association in the order CO₂ + PEG > CO₂ + PVAc > CO₂ + PSF > CO₂ + PMSSQ >> CO₂ + PVDF&PS. Specific interactions in polymer + CO₂systems were also investigated via NVT molecular dynamics simulations Such interactions were found to decrease in the order: CO₂...C-O-C > CO₂...O=C-O > CO₂...Si-O-Si. In addition, the association distance was identified to be 3.2 Å. Finally, CO₂ accessibility was found to decrease in the order PVAc > PVMK > PLA > PMA. It was also confirmed that 96 % of associated CO₂ molecules interact with one carbonyl group in these systems. A ternary extension of the Compressible Lattice Model (CLM) was developed and the enthalpy of specific interactions obtained from ATR_FTIR spectra was incorporated into the model to correlate and predict phase behavior in polymer + CO₂ + cosolvent systems. This work shows that model parameters obtained from binary data can be used to predict ternary system behavior with average absolute deviations between calculated and experimental values (AAD) less than 10%. The Sanchez-Lacombe lattice-fluid partition function was extended to associated systems by incorporating an association factor obtained from the Compressible Lattice Model. The resulting Associated Sanchez-Lacombe (ASL) EOS has the same form as the SL EOS, but includes the effects of specific interaction in the calculation of lattice energies, and chemical potentials. We demonstrate that ASL model parameters obtained from correlation of sorption equilibria can be used to predict swelling of polymers with AAD less than 10%. In summary, specific interactions between CO₂ and C=O and other CO₂-philic groups have been quantified using in situ ATR-FTIR spectroscopy. The results have been directly incorporated into a lattice model that is able to correlate cloud points, and sorption equilibria, using a single parameter. The model is therefore likely to be beneficial in many applications involving polymer + CO₂ or polymer + CO₂ + cosolvent systems including polymer impregnation, coating, foaming, and polymer membranes for CO₂ capture. An EOS formulation for the model has been derived for the calculation of swelling in these systems.

The melting points of rigid, hydrogen bonding, and non-hydrogen bonding organic compounds have been estimated from their chemical structure. The estimation was accomplished through the use of both additive and non-additive non-constitutive properties of the molecule. The melting points of the aforementioned compounds can be estimated by the equation: TM = TMPN + TIHBN + TPACK + 8.9*EXPAN + 73.1*SIGMAL + 196.3 where the dependent variable, TM, is the melting point of the compound in Kelvin, SIGMAL is the logarithm of the symmetry number for the molecule, EXPAN is the eccentricity of the molecule taken to the third power, TMPN is the summation of the melting point number for each functional group in the molecule, TIHBN is the summation of an intramolecular hydrogen bonding index and TPACK is a packing efficiency index. The solubility of naphthalene in binary, ternary, and quinary cosolvent-water mixtures was determined by HPLC analysis. The samples were equilibrated for 48 hours on a test tube rotator, centrifuged, diluted with acetonitrile, and then injected onto a C8 10 micron column. The cosolvent mixtures used were hydro-organic solutions consisting of water with either methanol, ethanol, isopropanol, acetone, acetonitrile, propylene glycol or a combination of these as the cosolvent. The propylene glycol-water mixtures were allowed to equilibrate for 10 days. In all cases, naphthalene solubilities in binary cosolvent mixtures were found to obey log-linear relationships: log X = SIGMA(FRAC) - log X(w) where X is the mole fraction solubility of naphthalene in the mixture, X(w) is the mole fraction solubility in pure water, FRAC is the volume fraction of the cosolvent, and SIGMA is the slope. SIGMA can be estimated by using the UNIFAC method to predict the solubility in 100% cosolvent and by using the generalized solubility equation of Yalkowsky to estimate the water solubility. These binary equations can then be used to generate ternary and higher multicomponent equations.

Acetic anhydride hydrolysis in water is considered a standard reaction for investigating activation energy parameters using cosolvents. Hydrolysis in water/acetonitrile cosolvent is monitored by measuring pH vs. time at temperatures from 15.0 to 40.0 °C and mole fraction of water from 1 to 0.750. This work utilizes a temperature controlled water bath and a Vernier glass-body pH probe with Vernier Logger Pro 3.10.1 software for automated data collection. Data analysis is used to determine observed kinetic rate constants under the assumption that hydrolysis is a pseudo-first-order reaction. Eyring plots were used to compare activation energy parameters under iso-mole fraction conditions. The hydrolysis reaction of acetic anhydride was enthalpically stabilized and entropically destabilized at mole fractions of acetonitrile greater than 0.17 and the reverse occurred at mole fractions less than 0.17. Activation enthalpy and entropy result in the reaction being less favorable to form products as mole fraction of acetonitrile increased.

Em muitos países e principalmente no Brasil, compostos oxigenados tais como etanol e metil terta-butil-éter (MTBE) têm sido adicionados à gasolina em cerca de 26% do seu volume para aumentar a octanagem do motor e diminuir a emissão de monóxido de carbono e os níveis de ozônio na atmosfera. O derramamento de tais gasolinas, referidas como gasolina oxigenada tem um efeito cosolvente, provocando um aumento da concentração dos hidrocarbonetos na água subterrânea. A taxa de dissolução em água da gasolina oxigenada, que é dependente das propriedades químicas dos compostos orgânicos, determinam o grau e a severidade de contaminação da água subterrânea nas vizinhanças do derramamento. O objetivo do trabalho foi analisar e quantificar o potencial de contaminação da água subterrânea e de solos arenosos residuais dos arenitos da Formação Botucatu por derramamento de gasolina oxigenada. As análises realizadas buscam fornecer dados para a modelagem numérica em casos envolvendo derramamento de gasolina. Ensaios de equilíbrio em lote e de dissolução em colunas foram realizados objetivando a determinação da concentração aquosa de hidrocarbonetos da gasolina em equilíbrio de fases e a avaliação do tempo estimado para total dissolução em água dos hidrocarbonetos da gasolina pura. Ambos os ensaios analisaram também o efeito cosolvente do etanol na mistura. Verificou-se a validade da lei de Raoult e do modelo log-linear na determinação da concentração aquosa da gasolina pura e oxigenada. Em colunas de solos não saturados avaliou-se a difusão na fase vapor dos compostos orgânicos da gasolina em função do tempo. Finalizando as análises, fez-se uma simulação numérica do transporte da gasolina em zonas não saturadas fazendo-se uso do programa R-UNSAT.
In many countries and mainly in Brazil oxygenated compounds such as ethanol and MTBE have been added to gasoline up to 26% to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The spill of such gasolines, referred as oxygenated gasoline has a potential cosolvent effect, resulting in an increased groundwater concentration of hydrocarbons. The rate of oxygenated gasoline dissolution, which is dependent of the chemical properties of the compounds, determines the degree and severity of groundwater contamination in the vicinity of the spill. The goal of this research was to analyze and to quantify the potential of contamination of the groundwater and of the residual sandy soils from Botucatu sandstone due to the spill of oxigenated gasoline. The performed analysis supply data to the numerical model in case of gasoline spills. Laboratory batch and column leaching tests were carried out in order to determine the equilibrium aqueous concentration of the hydrocarbons compounds of gasoline and to evaluate the time scale for aqueous dissolution of the hydrocarbons compounds. Both tests have analyzed the cosolvent effect of ethanol in the mixture. It was verified the validity of the Raoult's law and the log-linear cosolvency model to estimate the solubility of the hydrocarbons compounds from unamended gasoline and from oxygenated gasoline. Column tests with unsaturated undisturbed soil samples were carried out to investigate the vapor-phase diffusion of aromatic hydrocarbons compounds with time. Finally the transport of gasoline in unsaturated zones was simulated with the R-UNSAT model.

La cellulose est le polymère naturel le plus abondant. Cependant son utilisation est limitée par sa faible dissolution due à des liaisons hydrogènes intra et inter moléculaires. Jusqu’à aujourd’hui des solvants toxiques sont utilisés dans les procédés de dissolutions de la cellulose. Par conséquent de nouveaux solvants pour la dissolution de la cellulose ont été intensivement étudiés comme solutions de rechange de ces procédés polluants. Une des solutions est d’utiliser la technologie des fluides supercritiques utilisant le dioxyde de carbone. Malheureusement, la cellulose reste insoluble dans le CO2 dans les conditions supercritiques et il est donc important d'étudier un mélange binaire d’un co-solvant (organique ou liquide ionique) et le CO2 pour le développement d’un nouveau procédé. Cependant la connaissance du point fondamental des paramètres contrôlant le processus de dissolution dans ces fluides ralentit le développement de l’utilisation de cet outil propre et peu couteux en énergie. Nous avons donc utilisé la simulation de dynamique moléculaire pour caractériser le processus de dissolution de la cellulose dans ces fluides. Pour cela, nous nous sommes intéressés aux fluides supercritiques purs, puis aux mélanges des fluides supercritiques avec un co-solvant et enfin nous avons étudié le processus de dissolution de modèle de celluloses et de caractériser l’effet de la pression, la température, la composition du mélange ainsi que les propriétés structurales de ces modèles de cellulose sur le processus de dissolution
Cellulose is insoluble in neat supercritical CO2 and the main objective of this work was to investigate mixtures of scCO2 with polar cosolvents for the development of new processing technologies for the cellulose dissolution. The objective is achieved by studying the dissolution process of monomer of cellulose and its various polymorphs. The effect of the t/d parameters on the dissolution process was analyzed by molecular dynamics simulation. We begin with analyzing structure of pure supercritical fluids and mixtures of supercritical fluids/cosolvents using unconvential tools: Voronoi tesselations and nearest neighbours approach.Thermodynamics of the mixtures of scCO2/cosolvents is analysed in order to check the validity of the potential models used in our simulations for what the method of thermodynamic integration to calculate the energy, entropy and free energy of mixing was applied. To analyze the dissolution of cellulose we started from studying the solvation free energy of cellobiose(cellulose monomer) which was calculated from molecular dynamics simulations using free energy perturbation method. The influence of conformational degrees of freedom on solvation free energy of cellobiose was also considered.Finally, the direct dissolution of cellulose crystals models in well-known good cellulose solvent(1-ethyl-3-methylimidazolium chloride) and then considered supercritical solvents. It was found that various mixtures of CO2 with cosolvents do not dissolve cellulose but they can considerably affect its crystalline structure whereas ammonia fluid can dissolve cellulose and this process is significantly influenced by temperature, pressure and density

The hydrolysis of acetic anhydride is a widely-studied liquid phase reaction studied since 1906. Different approaches have been used to study the kinetics of this reaction. Approaches used by researchers have involved the use of sophisticated experimental set-ups. In this work, the pH technique has been adopted which involves the use of a pH meter to monitor the hydrolysis reaction. Analysis of the hydrolysis reaction has been performed for water/acetone cosolvent systems over a range of temperatures and mole fractions. Eyring analysis was performed under isomole fraction conditions and activation enthalpy, entropy, and Gibbs free energy for hydrolysis of acetic anhydride have been determined. The isomole fraction Eyring plots are linear, because, activation enthalpy and entropy are independent of temperature under these conditions. Activation free Gibbs energy increases with increasing temperature at a constant water mole fraction, while it decreases with increasing water mole fraction at constant temperature.

High-protein nutrition (HPN) bars (≥ 30% protein) have limited shelf life and become excessively hard during storage. Various mechanisms have been proposed to explain the hardening. The objectives of this research were to investigate the chemistry of HPN bar hardening and propose solutions for slowing it and improving bar texture. In phase 1, HPN bars were made containing 34% whey protein isolate (WPI) or milk protein concentrate (MPC) powder, along with either sorbitol syrup or glycerol, and vegetable shortening or cocoa butter. Substituting MPC for WPI made the bars brittle and crumbly. Using glycerol initially made bars softer but accelerated hardening. Cocoa butter increased bar hardness because of its higher solid to liquid content. Most water (~99%) in HPN bars made using sorbitol syrup is present as bound water, with ~0.9% as intermediate water and ~0.1% as bulk water. During storage bound water increased ~0.02 g/100 g of solids while intermediate water decreased, suggesting changes in state of water taking place at protein surfaces. During storage, there were changes in protein conformation indicated by an increase (~4°C) in heat denaturation temperature of β-lactoglobulin and α-lactalbumin and a 15 to 40% decrease in denaturation enthalpy. In phase 2, various bar formulations were tested involving different proportions of proteins, lactose, glycerol, and sorbitol syrup, as well as type of lipid component, and disulfide bonds inhibition. Decreases in bar hardening occurred when MPC and WPI and sorbitol syrup and glycerol were used in combination. In phase 3, HPN bars made with 38% protein powder as a 50:50 combinations of WPI and MPC and with 20% of sorbitol syrup substituted with glycerol, had good texture and minimal hardening during storage. Bar hardening was not caused by phase separation of protein and sorbitol, Maillard browning, or formation of inter-molecular disulfide bonds. Minimizing bar hardening requires prevention of entropy-induced protein aggregation by masking hydrophobic regions on protein surfaces and preventing formation of extended protein networks. It is proposed that preferential exclusion of cosolvents causes glycerol to be oriented at protein surfaces such that its carbon backbone masks hydrophobic regions thus avoiding a decrease in entropy of water molecules. (229 pages)

Class of 2015 Abstract
Objectives: To evaluate the in vitro performance of various pressurized metered dose inhaler (pMDI) formulations by cascade impaction primarily focusing on throat deposition, fine particle fraction (FPF), and mass-median aerodynamic diameter (MMADR) measurements Methods: Ten solution pMDIs were prepared with varying cosolvent species in either low (8% w/w) or high (20% w/w) concentration. The chosen cosolvents were either alcohol (ethanol, n-propanol) or acetate (methyl-, ethyl-, and butyl acetate) in chemical nature. All formulations used HFA-134a propellant and 0.3% drug. The pMDIs were tested by cascade impaction with three different inlets to determine the aerodynamic particle size distribution (APSD), throat deposition, and FPF of each formulation. Theoretical droplet evaporation time (DET), a measure of volatility, for each formulation was calculated using the MMADR. Results: Highly volatile formulations with short DET showed consistently lower throat deposition and higher FPF than their lower volatility counterparts when using volume-constrained inlets. However, FPF values were not significantly different for pMDI testing with a non-constrained inlet. The MMADR values generated with volume-constrained inlets did not show any discernible trends, but MMADR values from the non-constrained inlet correlated with DET. Conclusions: Formulations with shorter DET exhibit lower throat deposition and higher FPF, indicating potentially better inhalational performance over formulations with longer DET. There appear to be predictable trends relating both throat deposition and FPF to DET. The shift in MMADR values for volume-constrained inlets suggests that large diameter drug particles are preferentially collected in these inlets.

The contamination of soils, with polycyclic aromatic hydrocarbons (PAHs), remains a widespread environmental concern. In the past two decades, many physical, chemical and biological methods have been developed and evaluated for the degradation of PAHs. However, due to their low aqueous solubility, high sorption affinity, hydrophobicity and recalcitrance, the environmental remediation of PAHs in soil continues to be economically challenging. In addition to PAH contamination, the presence of oxygenated derivatives of PAHs (OPAHs), in soils, has increasingly become a concern due to their greater toxic properties compared to parent PAH compounds. To date, no investigations on OPAH-remediation methods have been presented in the literature. The use of zero-valent metals (ZVMs) has been reported for several halogenated contaminants in solution systems, but the effectiveness of ZVM to degrade sorbed PAHs and OPAHs has been rarely addressed. This present research focuses on the development of a combined technique for the feasible desorption and degradation of PAHs and OPAHs in soils. PAH and OPAH degradation efficiency, using activated magnesium (Mg) metal combined with an ethanol-ethyl lactate cosolvent (1:1 ratio), was initially examined in soil-free systems. This metal/cosolvent system demonstrated adequate degradation (above 80%) for high-molecular-weight (HMW) PAHs, which were subsequently converted into hydroaromatic compounds; while OPAHs were degraded and converted into hydroxylated or hydrogenated derivatives. Further soil-free studies revealed that the degradation rate was affected by the surface or reactive sites of the metal and that optimum degradation efficiency were obtained with Mg ball milled with graphite (Mg/C). In a bench-scale feasibility test, the efficacy of this system was assessed on a soil spiked with a mixture of three HMW PAHs compounds and three OPAHs compounds with amounts ranging from 0.033 mmol to 0.060 mmol. The experimental results show that 2 mL of an ethanol-ethyl lactate solvent mixture resulted in 58% to 85% extraction efficiency for the selected contaminants in 1 g of spiked soil, followed by 64 - 87% degradation efficiency of the extracted contaminants with 4.11 mmol of the activated metal. This activated-Mg/cosolvent system can be considered as a promising alternative method for ex situ remediation of PAH and OPAH-contaminated soils.
Ph.D.
Doctorate
Chemistry
Sciences
Chemistry

Mestrado em Engenharia Química
Nas últimas décadas, os fluidos supercríticos têm ganho maior destaque no âmbito dos paradigmas de biorrefinaria e sustentabilidade de processos químicos, surgindo como alternativa verde a muitos solventes orgânicos. Em particular, sendo o dióxido de carbono supercrítico (SC-CO2) o solvente preferido, são necessários valores experimentais e modelos preditivos de difusividades de solutos tanto em SC-CO2 puro como modificado com cossolvente. Esta tese surge como resposta à falta de dados e modelos nesta área, tendo como principal objetivo a medição e posterior modelação dos coeficientes de difusão de eucaliptol em SC-CO2 modificado com 8 % (m/m) de etanol e ainda etanol líquido puro. Recorrendo ao método cromatográfico de abertura de pico (CPB), procedeu-se à medição de difusividades do eucaliptol a diluição infinita (D12), numa gama de temperaturas entre 303.15 K e 333.15 K. Para a mistura SC-CO2 com etanol, a pressões de 150 a 275 bar, obtiveram-se valores compreendidos entre 0.547×10-4 a 1.042×10-4 cm2 s-1. Já em etanol puro, variando a pressão entre 1 e 100 bar, obtiveram-se difusividades entre 0.912×10-5 e 1.578×10-5 cm2 s-1. Os resultados de D12 foram analisados em função da temperatura, pressão, densidade e em coordenadas de Stokes-Einstein. Testou-se também uma série de modelos baseados nas teorias hidrodinâmica e de volume livre, bem como equações empíricas. Os valores calculados e experimentais foram comparados com base no desvio relativo absoluto médio (AARD). Para ambos os sistemas, destacam-se o modelo de dois parâmetros de Dymond-Hildebrand-Batschinski (DHB), o modelo Tracer Liu-Silva-Macedo com um parâmetro (TLSMd), um modelo modificado Stokes-Einstein-1, e as relações empíricas de Magalhães et al. (AARD entre 1.2 e 7.0 %). Em relação ao sistema ternário (eucaliptol na mistura SC-CO2 com etanol) os modelos de Wilke-Chang, Lai-Tan e Vaz et al. (AARD de 8.00, 8.36 e 1.29 %, respetivamente) foram os melhores. Quanto ao sistema binário (eucaliptol em etanol líquido) destaca-se ainda o modelo de Tracer Liu-Silva-Macedo (TLSM) (AARD de 6.75 %). Sugerem-se ainda correções a dois modelos, nomeadamente, à extensão do modelo de Liu-Silva-Macedo para intradifusividades em mixturas Lennard-Jones multicomponente, usando as regras de mistura propostas por Merzliak e Pfenning (LSM-MP) para o sistema ternário, e ao modelo DHB para o sistema binário, tendo-se obtido AARDs de 1.55 % e 3.70 %, respetivamente. Finalmente, procedeu-se à modelação de uma base de dados contendo 1453 pontos experimentais de difusividades correspondentes a 132 sistemas ternários distintos. Esta modelação foi realizada utilizando o modelo LSM-MP, ao qual foi proposta uma correção com base na divisão dos dados em 2 grupos: sistemas líquidos e supercríticos (AARDs de 9.39 % e 9.11 %, respectivamente).
Supercritical fluids have gained great importance within the concepts of biorefinery and sustainability of chemical processes. They are considered a “greener” alternatives to a vast group of conventional organic solvents with supercritical carbon dioxide (SC-CO2) being the most preferred. Currently, experimental data and predictive models for diffusivity in SC-CO2 systems are scarce especially regarding SC-CO2 systems modified with a cosolvent. The main objective of this thesis was the experimental determination and modelling of tracer diffusion coefficients (D12) of eucalyptol in SC-CO2 expanded with 8 wt.% ethanol (ternary system) and in pure ethanol (binary system). Furthermore improve the D12 modelling in multicomponent mixtures. Eucalyptol diffusivities were measured by the chromatographic peak broadening technique (CPB) in the temperature range 303.15 to 333.15 K. For the ternary system the values ranged from 0.547×10-4 to 1.042×10-4 cm2·s-1 for pressures between 150–275 bar. For the binary system the values ranged from 0.912×10-5 to 1.578×10-5 cm2·s-1 for pressures between 1-100 bar. The dependency of D12 in terms of temperature, pressure, solvent density, and Strokes-Einstein coordinates were also examined. A series of models based on hydrodynamic and free volume theory and on empirical correlations were tested and compared using the average absolute relative error (AARD) for calculated and experimental values. For both systems, the best results were obtained with the two parameter Dymon-Hildebrand-Batschinski (DHB) model, with the one parameter Tracer Liu-Silva-Macedo (TLSMd) model, with the modified Stokes-Einstein-1 model, and with the Magalhães et al correlations (AARD between 1.2 and 7.0 %). For the ternary system the Wilke-Chang, Lai-Tan, and Vaz et al. models can also be highlighted (achieving AARD of 8.00, 8.36 and 1.29 % respectively). For the binary system the TLSM model achieves an error of 6.75 %. In addition, two corrections are presented to improve model fitting, namely for the extension of Liu-Silva-Macedo model to multicomponent LJ intradiffusivities using mixing rules of Merzliak and Pfenning (LSM-MP) applied to the ternary system and for the DHB model applied to the binary system (AARD of 1.55 % and 3.70 %, respectively). Finally a database containing 132 ternary systems with a total of 1453 experimental diffusivity values was utilized for modeling D12 values, on the basis of the LSM-MP model. The AARD results obtained by splitting the database into two groups, namely liquid and supercritical systems, were 9.39 and 9.11 % respectively.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Candeia (Eremanthus erythropappus) is a native species of the Brazilian Atlantic forest from which an essential oil with high concentration of sesquiterpene α-bisabolol is extracted. α-Bisabolol is an active principle of important application in the cosmetic and pharmaceutical industries due to its anti-inflammatory, antispasmodic, sedative, antiallergic, anti-irritant, cicatrizant and vermifugal properties. Steam distillation is the most common method used to obtain this oil, with requires long periods of time extraction besides the degradation of thermosensitive compounds. Within this context, the aim of this study was to evaluate the quality of the candeia wood oils obtained by non-conventional methods of extraction (supercritical technology by using carbon dioxide and cosolvents, pressurized liquid and ultrasound-assisted extraction), in terms of oil yield, bisabolol content and antioxidant activity. In addition, the oil re-extraction from the industrial residue was also evaluated. The extractions were carried out with CO2 at temperatures of 40, 55 and 70 oC and pressures of 160, 200 and 240 bar, with a solvent mass flow rate of 1.96 x 10−3 kg min−1 and 120 min of total extraction. The highest extraction yield obtained was 1.42 wt% for the candeia wood and 0.41 wt% for the residue, both at 70 oC and 240 bar, and this condition was selected to perform the extractions using cosolvents. Ethanol and ethyl acetate were added to supercritical CO2 at concentrations of 1, 3 and 5 % (v/v), obtaining up to 2.35 wt% of yield. The Soxhlet (360 min) and pressurized liquid (40, 55 and 70 oC; 100 bar and 20 min) extractions showed the affinity of the candeia compounds for polar solvents and the positive effect of the temperature on the yield, which varied from 0.53 to 7.23 wt%. A Box-Benhken design was employed to evaluate the effect of the variables temperature (40, 50 and 60 oC), n-hexane volume to wood mass (10, 15 and 20 mL g-1) and nominal power (150, 300 and 450 W) on the yield of ultrasound-assisted extractions, obtaining in 7 minutes of extraction, up to 83% of the yield obtained in the conventional technique in Soxhlet (1.57 wt%), with a solvent volume 2.5 times smaller. The major compounds identified in the candeia oil were the sesquiterpenes α-bisabolol, eremanthin and costunolide, and the α-bisabolol content in the oil is favored by the lowest CO2 density, with 74.45 % being obtained for the candeia wood and 50.62 % for the residue, in both cases in oil extracted at 70 oC and 160 bar. The addition of ethanol and ethyl acetate cosolvents to CO2 increased the α-bisabolol yield by 41 %. Also, the cosolvents increased the amount of total phenolic content in the oil, and consequently, its antioxidant capacity. The oil fractionation by column chromatography was efficient for α-bisabolol isolation. However, unlike the candeia wood oil, this compound was not effective in inhibiting the Staphylococcus aureus growth. In relation to the supercritical extractions, the Sovová mathematical model presented a good adjustment to the experimental data for all the conditions used.
A candeia (Eremanthus erythropappus) é uma árvore nativa da Mata Atlântica da qual se extrai um óleo essencial com elevada concentração do sesquiterpeno α-bisabolol, princípio ativo de grande aplicação nas indústrias de cosméticos e farmacêutica devido às suas propriedades anti-inflamatória, antiespasmódica, sedativa, antialérgica, anti-irritante, cicatrizante e vermífuga. A obtenção deste óleo em escala industrial é realizada pelo processo de destilação por arraste a vapor, com elevado tempo de extração, além da degradação de compostos termossensíveis. Neste contexto, o presente trabalho tem como objetivo avaliar a qualidade dos óleos da madeira de candeia, obtidos por métodos não convencionais de extração (tecnologia supercrítica com dióxido de carbono e cossolventes, líquidos pressurizados e solvente assistido por ultrassom), em termos de rendimento, teor de α-bisabolol e atividade antioxidante. Ainda, avaliar a re-extração do óleo do resíduo industrial. As extrações foram realizadas com CO2 nas temperaturas de 40, 55 e 70 oC e pressões de 160, 200 e 240 bar, com vazão mássica de solvente de 1,96 x 10-3 kg min-1 e tempo total de 120 minutos. O maior rendimento obtido para o óleo da candeia nas extrações supercríticas foi de 1,42 % e de 0,41 % para o resíduo, ambos em 70 oC e 240 bar, condição selecionada para os experimentos com cossolventes. Os solventes etanol e acetato de etila foram utilizados nas concentrações de 1, 3 e 5 % (v/v) junto ao CO2, proporcionando rendimentos de até 2,35 %. As extrações Soxhlet (360 min) e com líquidos pressurizados (40, 55 e 70 oC; 100 bar e 20 min) evidenciaram a afinidade dos compostos por solventes polares e o efeito positivo da temperatura sobre o rendimento, de 0,53 a 7,23 %. Um planejamento Box-Behnken foi empregado para avaliar efeitos da temperatura (40, 50 e 60 oC), razão volume de n-hexano/massa de madeira (10, 15 e 20 mL g-1) e potência ultrassônica nominal do equipamento (150, 300 e 450 W) sobre rendimento em óleo, obtendo-se, em 7 minutos de extração, até 83 % do rendimento obtido na técnica convencional em Soxhlet (1,57 %), com volume de solvente 2,5 vezes menor. Os compostos majoritários identificados no óleo da candeia foram os sesquiterpenos α-bisabolol, eremantina e costunolida, e o conteúdo do α-bisabolol no óleo foi favorecido pela menor densidade do CO2 supercrítico, sendo de até 74,5 % para a madeira de candeia e 50,6 % para o resíduo, ambos extraídos na condição de 70 oC e 160 bar. A adição dos cossolventes etanol e acetato de etila ao CO2 elevou o rendimento de α-bisabolol em até 41 %. Também aumentaram a quantidade de fenólicos totais no óleo e, consequentemente, sua capacidade antioxidante. O fracionamento do óleo por cromatografia em coluna foi eficiente para o isolamento do α-bisabolol. No entanto, diferentemente do óleo da madeira de candeia, este composto não foi efetivo na inibição do crescimento de Staphylococcus aureus. Em relação às cinéticas das extrações supercríticas, o modelo matemático de Sovová se ajustou aos dados experimentais em todas as condições utilizadas.

The development of selective SmI2-H2O-mediated mono-reductions of cyclic-1,3-diesters to the corresponding 3-hydroxy acids is described. The reaction proceeds with complete selectivity for cyclic-1,3-diesters over acyclic esters. Sequential one-pot conjugate reduction-ester reduction of alkylidene cyclic-1,3-diesters is also reported. Furthermore, we describe the exploitation of the unusual ketyl radical intermediates formed via single electron reduction of the ester carbonyl in unprecedented 5-exo-trig cyclisations providing access to highly substituted, stereo-defined, cyclopentanols and cyclopentanones. Also described is the use of a silicon control element to direct the stereochemical outcome of the SmI2-MeOH-mediated conjugate reduction-intramolecular aldol cyclisations of α,β-unsaturated lactones. These cyclisations generate two contiguous quaternary centres with complete diastereocontrol; the utility of the silicon-directing group as a synthetic handle for derivatisation of the cyclisation products has also been demonstrated. These cyclisations have been applied in a model approach to the anti-mitotic natural product pseudolaric acid B.

The goal of this work was to study the use of Eutectic Solvents (ESs) for wood fractionation aiming at their application on pulping processes, in the biorefinery framework. To achieve this purpose, fundamental studies were performed to better understand the solubility of lignin monomer model compounds (syringaldehyde and syringic, vanillic and ferulic acids) and technical lignins (kraft and organosolv) in ESs and their aqueous solutions. Particularly, aqueous solutions of propionic acid:urea (2:1) at 50 or 75 wt % of concentration and 353.15 K improved lignin solubility by two orders of magnitude in comparison to water and conventional lignin solvents [solubility enhancement of (228.3 ± 8.2)- and (474.7 ± 2.7)-fold for kraft and organosolv lignin, respectively]. Furthermore, maximum solubilization of lignin monomer model compounds was achieved using ethylene glycol:tetrabutylphosphonium chloride (2:1) aqueous solutions at 50 or 75 wt % of concentration and 323.15 K [(34.9 ± 6.7)-, (116.6 ± 1.6)-, (58.6 ± 0.4)- and (202.5 ± 16.9)-fold, respectively]. It should be highlighted the fundamental role of water, which allows a hydrotropic effect on lignin (and their monomers) solubility in these ESs aqueous solutions. The best ESs to enhance the solubility of lignin in water was used to develop a new wood delignification process. Therefore, delignification of Eucalyptus globulus wood catalyzed by mineral or organic acids in ESs aqueous solutions was studied. The results obtained confirmed that the wood delignification using ESs aqueous solutions requires the addition of acid catalyst in order to enhance lignin removal. Two different ESs aqueous systems were identified as the best to delignify E. globulus wood under mild conditions: (i) the 50 wt % aqueous solution of propionic acid:urea (2:1) in the presence of 25 wt % of p-toluenesulfonic acid as catalyst (8 h, 363.15 K and atmospheric pressure). This system led to the production of a solid fraction yield of 59.50 ± 0.51 wt %, containing a residual Klason lignin of 3.86 ± 0.10 wt % with preserved cellulose fibers, when compared to conventional E. globulus kraft pulp; and (ii) the 50 wt % aqueous solution of ternary-ESs mixture (sodium p-toluenesulfonate:p-toluenesulfonic acid:choline chloride) at optimal molar ratio of (0.393:0.376:0.232) that allowed producing 46.60 ± 2.70 wt % of solid fraction yield, containing a residual Klason lignin of 2.74 ± 0.08 wt % under milder conditions (3 h, 363.15 K and atmospheric pressure). Moreover, the chemical structural analysis of both isolated lignins revealed that fewer transformations are induced by these systems, when compared to E. globulus kraft, and other ESs reported in literature. Finally, promising preliminary results show the feasibility for scaling the ES wood delignification process using both ESs.
Este trabalho teve como objectivo estudar o uso de solventes eutécticos (SEs) no fraccionamento de madeira, com vista à sua aplicação em processos de produção de pasta, no âmbito de uma biorrefineria. Nesse sentido, foi desenvolvido um estudo fundamental que permitisse compreender a solubilidade de lenhinas técnicas (kraft e organosolv) e dos seus monómeros (siringaldeído e ácidos siríngico, vanílico e ferúlico) nos SEs puros e respetivas soluções aquosas. Mostrou-se que, soluções aquosas de ácido propiónico:ureia (2:1) com concentrações de 50 ou 75 % m/m a 353.15 K aumentam a solubilidade da lenhina em duas ordens de grandeza relativamente à sua solubilidade em água pura ou solventes orgânicos convencionais usados normalmente para a solubilização de lenhina [aumento de solubilidade de (228.3 ± 8.2)- e (474.7 ± 2.7)-vezes para as lenhinas kraft e organosolv, respectivamente]. Além disso, foi possível obter uma solubilização máxima dos monómeros de lenhina usando uma solução aquosa de etileno glicol:cloreto de tetrabutilfosfónio (2:1) com concentrações de 50 ou 75 % m/m a 323.15 K [(34.9 ± 6.7)-, (116.6 ± 1.6)-, (58.6 ± 0.4)- e (202.5 ± 16.9)-vezes, respectivamente]. É de salientar o papel fundamental da água que permite o efeito hidrotrópico na solubilização da lenhina e seus monómeros nas soluções aquosas dos SEs estudados. De seguida, os melhores SEs foram usados no processo de deslenhificação de madeira de Eucalyptus globulus como prova de conceito. O efeito da adição de catalizadores ácidos foi igualmente estudado. Os resultados obtidos confirmaram que a adição de um catalizador ácido às soluções aquosas de SEs promovem a extração de lenhina. Neste estudo, dois sistemas aquosos de SEs (50 % m/m) apresentaram resultados excelentes na deslenhificação da madeira de E. globulus: (i) ácido propiónico: ureia (2:1) na presença de 25 % m/m de catalisador ácido ptoluenosulfónico (8 h, 363.15 K e pressão atmosférica). Este sistema resultou num rendimento de fração sólida de 59.50 ± 0.51 % m/m, contendo 3.86 ± 0.10% m/m de lenhina Klason residual. A análise da pasta resultante permitiu concluir que as fibras de celulose foram preservadas quando comparadas com a pasta kraft de E. globulus; e (ii) mixtura ternária (p-toluensulfonato de sódio: ácido p-toluenosulfónico:cloreto de colina) numa razão molar óptima de (0.393:0.376:0.232) nas condições óptimas de operação de 3 h, 363.15 K e pressão atmosférica. Este sistema resultou num rendimento de fração sólida de 46.60 ± 2.70 % m/m, contendo 2.74 ± 0.08 % m/m de lenhina Klason residual. As análises químicas estruturais realizadas às lenhinas isoladas revelaram menos modificações induzidas pelos sistemas propostos, quando comparados com a lenhina kraft de E. globulus ou outros sistemas SEs reportados na literatura. Por fim, estudos preliminares de aumento de escala usando os SEs propostos revelaram-se promissores.
Programa Doutoral em Engenharia Química

Diese Dissertation beschäftigt sich mit der passiven Probenahme von hydrophoben organischen Schadstoffen in Oberflächengewässern: Polyaromatische Kohlenwasserstoffe (PAK), polychlorierte Biphenyle (PCB), polybromierte Biphenylether (PBDE), Organochlorpestizide (u. a. HCH, DDX) und weitere hydrophobe Pestizide. Die Zielstellung dieser Arbeit lag bei der Validierung des Silikonstabs als Alternativmethode im Gewässermonitoring zu konventionellen Probenahmetechniken wie Schöpf- und Wochenmischproben der Wasserphase sowie Schwebstoffanalysen. Die Probenahme mit dem Silikonstab erfolgte durch dessen Exposition im Gewässer für einen Zeitraum zwischen einer Woche und mehreren Monaten. Nach Einholung wurden die im Silikonstab akkumulierten Schadstoffe (Analyten) mittels instrumenteller Analytik quantifiziert. Die Probenaufgabe erfolgte ohne vorherige Lösungsmittelextraktion durch direktes Erhitzen des Silikonstabs, wodurch die Analyten vom Polymer desorbieren (Thermodesorption). Die durch Hitze freigesetzten Analyten wurden direkt auf eine chromatographische Trennsäule gegeben und massenspektroskopisch quantifiziert. Nach Erhalt der Ergebnisse der Silikonstab-Analytik gibt es verschiedene Herangehensweisen für die Berechnung der zeitgemittelten Analytkonzentrationen im Gewässer, die in dieser Arbeit vorgestellt und diskutiert werden. Dazu gehören die Verwendung von experimentellen Daten aus Kalibrierversuchen und Berechnungen auf Grundlage von physikochemischen Eigenschaften der Analyten wie dem Sammler-Wasser-Verteilungskoeffizienten. Im Zuge dieser Arbeit wurde die Aufnahmekinetik des Silikonstabs bei verschiedenen Temperaturen und Fließgeschwindigkeiten mit Hilfe von Kalibrierversuchen untersucht. Die gewonnenen experimentellen Daten wurden für die Entwicklung von Rechenmodellen herangezogen, mit denen das Aufnahmeverhalten vorgesagt werden soll. Es wurden Sammler-Wasser-Verteilungskoeffizienten für den Silikonstab u. a. mit der Kosolvenzmethode bestimmt und als Parameter für die Berechnung von zeitgemittelten Analytkonzentrationen des Gewässers verwendet. Für die Validierung wurde der Silikonstab in zwei Gewässergütemessstationen der Fließgewässer Mulde (Dessau) und Elbe (Magdeburg) in Durchflussbehältern exponiert und die zeitgemittelten Analytkonzentrationen mit verschiedenen Rechenmodellen bestimmt. Die erhaltenen Werte werden mit gleichzeitig entnommenen Wochenmischproben der Wasserphase sowie monatlichen Schwebstoffproben verglichen und die Eignung des Silikonstabs als alternative Probenahmemethode für das Umweltmonitoring von Oberflächengewässern diskutiert.:I ZUSAMMENFASSUNG ...................................................................................................... 2 II INHALTSVERZEICHNIS .................................................................................................. 3 III ABBILDUNGSVERZEICHNIS .......................................................................................... 5 IV TABELLENVERZEICHNIS ................................................................................................ 6 V GLEICHUNGSVERZEICHNIS ............................................................................................ 7 VI ABKÜRZUNGSVERZEICHNIS........................................................................................... 9 0 VIELEN DANK AN … ...................................................................................................... 11 1. EINLEITUNG ................................................................................................................ 12 1.1 Wasser, seine Nutzung und Verschmutzung ............................................................ 12 1.2 Das Wasser und seine Schadstoffe .......................................................................... 15 1.3 Monitoring von Oberflächengewässern .................................................................... 17 1.3.1 Entnahme konventioneller Schöpfproben .............................................................. 17 1.3.2 Entnahme von Mischproben (integrative oder Kompositproben) ........................... 18 1.3.3 Probenahme des Schwebstoffanteils in der Wasserphase .................................... 19 2. PASSIVSAMMLER IN DER WASSERANALYTIK ................................................................ 21 2.1 Theoretische Grundlagen ......................................................................................... 21 2.1.1 Allgemeiner Aufbau von Passivsammlern ............................................................... 23 2.1.2 Die einzelnen Schritte von der Wasser- in die Sammelphase ................................ 25 2.1.3 Adsorptive und absorptive Akkumulation des Analyten in der Sammelphase ........ 26 2.2 Passivsammlersysteme in der Wasseranalytik ......................................................... 28 2.2.1 Absorbierende Passivsammler für hydrophobe Analyten ....................................... 28 2.2.1.1 Semipermeable membrane device (SPMD) .......................................................... 28 2.2.1.2 LDPE-Streifen (LDPE strips) ................................................................................ 29 2.2.1.3 Silikonplatten (silicone sheets) ........................................................................... 30 2.2.1.4 Chemcatcher ...................................................................................................... 31 2.2.1.5 Lösungsmittelfreie Passivsammler (MESCO / Silikonstab) .................................. 32 2.2.2 Absorbierende Passivsammler für polare Analyten ............................................... 35 2.2.2.1 Polar organic integrative Sampler (POCIS) ......................................................... 35 2.2.2.2 Chemcatcher ...................................................................................................... 35 2.3 Auswertung von Passivsammlerdaten ..................................................................... 35 2.3.1 Gleichgewichtssammler ......................................................................................... 36 2.3.2 Laborkalibrierung .................................................................................................. 37 2.3.3 In-situ-Kalibrierung mit Performance Reference Compounds (PRC) ...................... 38 2.3.4 Validierung von Passivsammlern............................................................................ 39 3. LÖSLICHKEIT UND THERMODYNAMISCHES GLEICHGEWICHT ...................................... 41 3.1 Freie Enthalpie und chemisches Potential ................................................................ 41 3.2 Lineare freie Energie-Beziehungen (LFER) für die Abschätzung von KSW ................ 41 3.3 Kosolvenzmodelle für die Modellierung von KSW ...................................................... 43 3.3.1 Log-Linear-Modell von Yalkowsky .......................................................................... 43 3.3.2 Freie Enthalpie-Ansatz (Khossravi-Connors-Modell) .............................................. 44 3.3.3 Jouyban-Acree-Modell ............................................................................................ 44 4. MATERIAL UND METHODEN ......................................................................................... 45 4.1 Präparation der verwendeten Passivsammler .......................................................... 45 4.2 Laborkalibrierung zur Bestimmung von Sammelraten ............................................... 45 4.2.1 Beschreibung der Versuche für die Silikonstab-Kalibrierung .................................. 45 4.3 Experimentelle Bestimmung von Sammler-Wasser-Verteilungskoeffizienten KSW ... 48 4.3.1 Zeitabhängige KSW-Bestimmung in der Wasserphase .......................................... 48 4.3.2 KSW-Bestimmung mit der Kosolvenzmethode ....................................................... 50 4.4 Validierung des Silikonstabs an limnischen Gewässergütemessstationen ............... 52 5. ERGEBNISSE UND DISKUSSION ................................................................................... 55 5.1 Sammelraten RS für den Silikonstab aus Kalibrierversuchen .................................... 55 5.1.1 Temperaturabhängigkeit ....................................................................................... 58 5.1.2 Einfluss der Hydrodynamik auf die Aufnahmekinetik von PAK ................................ 59 5.1.3 Modellierung von Sammelraten .............................................................................. 62 5.1.3.1 Polynomisches Modell nach Vrana [137] ............................................................. 62 5.1.3.2 Diffusionsmodell nach Booij [71] ......................................................................... 64 5.1.3.3 Diffusionsmodell nach Rusina [85] ...................................................................... 66 5.1.4 Wahl der geeigneten In-situ-Kalibrierung am Beispiel eines Kalibrierversuchs ..... 67 5.1.4.1 Berechnung von In-situ-Sammelraten mit RS-Modellen ...................................... 68 5.1.4.2 Berechnung von In-situ-Sammelraten über Eliminierung von PRCs .................... 69 5.1.4.3 Vergleich Modelle und PRCs mit experimentellen Sammelraten .......................... 70 5.2 Experimentelle Bestimmung des Sammler-Wasser-Verteilungskoeffizienten KSW ... 73 5.2.1 Zeitabhängige KSW-Bestimmung in der Wasserphase .......................................... 73 5.2.2 Zusammenfassung KSW(t)-Versuche in der Wasserphase .................................... 81 5.2.3 KSW-Bestimmung mit der Kosolvenzmethode ....................................................... 81 5.2.3.1 Kosolvenzmodelle ............................................................................................... 83 5.2.4 Zusammenfassung ................................................................................................ 90 5.3 Empirische Modelle zur Abschätzung von KSW-Werten ............................................ 92 5.3.1 Lineare Korrelation des KSW mit physikochemischen und Molekülparametern ...... 92 5.3.2 Berechnung mit Mehrparameter-Regression (LSER) .............................................. 95 5.3.3 Zusammenfassung Abschätzung von KSW-Werten für den Silikonstab ................. 97 5.4 Freilandvalidierung des Silikonstab-Passivsammlers ................................................ 97 5.4.1 Ausbringung an Gewässergütemessstationen....................................................... 97 5.4.1.1 Validierung des Silikonstabs mit Wasserproben ............................................... 100 5.4.1.2 Validierung des Silikonstabs mit Sedimentproben ............................................ 102 5.4.2 Validierung des Silikonstabs bei Laborvergleichsstudien ..................................... 105 6. ERGEBNISSE UND AUSBLICK ..................................................................................... 105 VII LITERATURVERZEICHNIS ......................................................................................... 107 VIII ANHANG ................................................................................................................. 116

碩士
國立中央大學
化學工程與材料工程研究所
92
The solubility of a solid in a supercritical fluid is effected by temperature, pressure. And in some cases, an added cosolvent is utilized in the supercritical fluid extraction process. Therefore, the equilibrium data in supercritical fluids and the appropriate thermodynamic models that can accurately predict the phase behavior of the system are the important information for the design of such process and the selection of optimal operating conditions In this study, the solubilities of ��-carotene in pure supercritical carbon dioxide and with the cosolvents of ethanol, acetone, and n-hexane were measured from 15 MPa to 28 MPa (150 bar to 280 bar ) in temperature range from 313.15 K to 333.15 K by using a semi-flow type apparatus. Then all experimental data were correlated by the Peng-Robinson equation of state (PR EOS) with the VDW2 mixing rule and the density-based semi-empirical models of Chrastil、Mendez-Santiago and Jiang.

碩士
國立中央大學
化學工程與材料工程學系
104
In the study, we use Peng-Robinson + COSMOSAC equation of state (EOS) to predict the solubility of solid solutes in supercritical carbon dioxide (SCCO2) with cosolvent. We collected solubility data including 23 solid solutes from literatures published in recent years and we used the model to calculate solubility and discussed results. We also added optimized parameter which was proposed by Wang and Lin [1] to improve prediction accuracy for solids with ring structure. In the study, 23 solid solutes including 60 systems were calculated. ( T = 298.15－353 K, P = 0.1－40 MPa, and about 1126 solubility data.) The ALD-x (average logarithmic deviation in solubility) is 0.77 and decreased to 0.64 when adding the optimized parameter in program. This result is similar to the Wang and Lin ‘s, that is, PR + COSMOSAC EOS can predict the solubility of solid solutes not only in SCCO2, but also in SCCO2 with cosolvents. Moreover, melting temperature (Tm) and heat of fusion (Hm) of a solid compound are required in the method. It is found that experimental results of Tm and Hm from different research groups are different. These errors cannot be neglected. Therefore, choosing suitable Tm andHm of solid compounds can increase prediction accuracy. We think our prediction result is acceptable and we still devote to optimizing the parameter of the method. Furthermore, PR+COSMOSAC EOS is also a useful tool in the future, especially for solid compounds whose experimental data are difficult to obtain.

碩士
國立臺灣科技大學
化學工程系
88
The dissolution rates of three dispersion dyestuffs in supercritical carbon dioxide have been investigated experimentally with a semi-flow type apparatus at 393.2 K and 30 MPa. The magnitudes of the dissolution rates were found to be in the order of Blue 79 > Yellow 119 > Red 153. With ethanol as a co-solvent, the equilibrium solubilities of these three disperse dyes in supercritical carbon dioxide were measured, respectively, at 393.2 K and in pressure range of 20 to 30 MPa. The solubilities were enhanced by the presence of the co-solvent. The Chrastil equation correlated these isothermal solubility data to within experimental uncertainty. The correlated results showed that the association numbers, k, followed the sequence of the molecular size of the dyestuffs; i.e., Blue 79 > Red 153 > Yellow 119.

碩士
國立臺灣科技大學
化學工程系
91
Abstract The present study contains three major phases: (1) Measurement of relative dissolution rate of three dispersion dyestuffs (Blue 79:1,Red 82, and Yellow 119) in supercritical CO2 and N2O at 393.15 K and 30 MPa,respectively; (2) Measurement of the saturated solubilities of these three disperse dyes in supercritical CO2 and N2O at temperatures from 353.15 K to 393.15 K and pressures from 15 MPa to 30 MPa; (3) Investigation of cosolvent effects on the saturated solubility of three dyes. All the experiments were carried out by using a semi-flow type apparatus. The experimental results showed that the magnitudes of dissolution rate follow the order of Red 82 > Blue 79:1 > Yellow 119. At the same T and P, the saturated solubilities of the disperse dyestuffs are also follow the same sequence. It was also found that the saturated solubility of Yellow 119 in supercritical N2O is significantly higher than that in supercritical CO2. However, there are color-changed for Red 82 and Blue 79:1 after SF-N2O extraction. Adding ethanol as a cosolvent was capable of substantially increasing the saturated solubilities in the supercritical fluids for these dyestuffs. The solubility data can be correlated by the Chrastil model and the Santiago-Teja model reasonably well, and successfully passed the consistency test with the Santiago-Teja model.

碩士
國立交通大學
材料科學與工程系所
97
During the last few years, increased effort and work has been devoted to the development of solar cells based on conjugate polymer, however, there is a lacking of knowledge on how to take the laboratory stage organic photovoltaics into next level commercialized products. In this thesis, we report the large area, interconnected polymer solar cell modules on flexible substrate to outperform the traditional silicon solar cells in turn of light-weight, flexibility, and convenience. Here we use cosolvent system to assemble photoactive polymer blend, regioregular poly(3-hexylithiophene) (P3HT) : [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) on the flexible polycarbonate (PC) substrate coated with indium zinc oxide (IZO) and to induce effective phase separation in the active layer without the need of high temperature annealing process which is proven to be harmful to the plastic substrate. The morphological characterization is carried out with ultraviolet-visible spectroscopy (UV-VIS) and x-ray diffraction (XRD) and transmission electron microscopy (TEM). The IV characteristics of solar cell devices are performed under solar simulator (AM1.5). Through analyzing and balancing the solubility parameters of various cosolvent combinations towards each polymer blend material, we are able to control the morphology and crystallinity of P3HT material inside the polymer blend thus achieve a highest efficiency of 3.2 % for single solar cell device on plastic substrate without post annealing. In the second part of this thesis, we analyze the factors that determine solar module’s internal resistance, fill factor and power conversion efficiency. According to the experimental results, we have found that area of single cell, number of connected module, and solvent system used in manufacturing are all critical factors in optimizing overall performance of organic solar cell module. Hence, two different connection schemes (series and parallel) are applied to maximize the performance of solar modules. With a total of 24 solar cell devices (total active area = 24 cm2) interconnected on the 7 cm × 7 cm flexible panel, our organic solar module can output a short circuit current of 31 mA, an open circuit voltage of 1.8 V and a maximum power of 16.9 mW.

碩士
國立成功大學
化學工程學系碩博士班
91
Three ion pair amphiphiles (IPAs), derived from a series of alkyl trimethyl ammonium chlorides and sodium dodecyl sulfate, were used to form catanionic vesicles in water upon mechanical dispersion method. For the first time in the literature, short-chained alcohols (methanol, ethanol, n-propanol, and n-butanol) were added as cosolvents and studied systematically for their effects on the stability of the ensuing vesicles. Dynamic light scattering measurements indicated that one of the IPAs (i.e. DTMA‧DS) can be efficiently and successfully stabilized by the addition of suitable amounts of n-parpanol and n-butanol. More than three months storage period for stable vesicles was observed and this demonstrates that a novel method for stabilization of catanionic vesicles becomes available by means of cosolvent addition. Moreover, an explanation based on the medium dielectric effect was proposed. According to this mechanism, cosolvent addition may affect both the interaction between hydrophilic groups and that between the hydrophobic groups of the IPAs. With decreasing the dielectric constant of the mixed solvent by increasing the concentration of the cosolvent, the attractive interaction between polar groups will be strengthened on one hand the solvophobic effect of hydrophobic groups will be weaken on the other hand. These two opposite effects counterbalance each other and result in variations of vesicle stability with cosolvent concentration.

碩士
國立高雄師範大學
生物科學研究所
89
In-situ flushing is one of the promising remediation techniques in soil and groundwater contaminated sites. In dealing with lots of impacted sites in Taiwan, it is essential to develop a cost-effective technique to clean up the contaminants. The objective of this study is to evaluate removal efficiency of organic contaminants in contaminated soil by cosolvent flushing technique. Various volume fractions of cosolvent were applied in the laboratory scale study. The diesel contaminated soil was packed into glass columns then flushed with five to ten pore volumes of either single cosolvent (methanol, ethanol, or acetone), mixture cosolvents (ethanol + pentanol), or cosurfactant (ethanol + Makon 10) by pumping system. Sixteen polynuclear aromatic hydrocarbons (PAHs) were selected as target compounds to evaluate removal efficiency of various cosolvents. The result suggested that when single cosolvent was utilized, the removal efficiency is about 80% of 16PAHs. For mixture of cosolvent, it illustrated better removal efficiency to about 90% of 16PAHs. However, cosurfactant has the least removal efficiency of 70%. It is suggested that 50% ethanol or 10% pentanol plus 25% ethanol selection for remediation practice purpose in removing contaminants. This study will assist further understanding of in-situ flushing technique and decision making processes when field practice of soil and groundwater remediation is employed.

碩士
國防大學理工學院
化學工程碩士班
100
Reaction of gasous chlorotrifluoroethylene (F2C=CFCl) with sodium ethoxide under -78oC gives 1-ethoxy-1,1,2-trifluro-2-chloroethane (CFHClCF2OEt). Hydroly- sis of CFHClCF2OEt with sulfuric acid at 0 oC affords ethyl chlorotrifluoroacetate (CFHClCO2Et). Difloro methylene (CF2) group is transferred to the carbonyl group (C=O) during the hydrolysis process. The starting material fluorocarbonethoxymeth- ylene diethylphosphonates (EtO)2P(O)CFHCO2Et is prepared from the Michaelis- Arbuzov reaction of triethyl phosphates ((EtO)3P) with CFHClCO2Et at 140oC. Reaction of [R2P(O)CFCO2Et]-Li+ anion with aldehydes (RCHO) and ketones (RC(O)R’) in tetrahydrofuran (THF) via Horner-Wadsworth-Emmons (HWE) reaction gives the vinyl mono-fluorine compounds (E,Z)-RCH=CFCO2Et and RR’C=CFCO2Et, respectively. These compounds which put the ester group at α-carbon position and different substituents at β-carbon position act as the precursor to the bioactive compounds. The stereoselectivity of the products depend on the cosolvents and metal ion presented in the reaction mixture. The results show that in the presence of hexamethylphosphoric triamide (HMPA), the ratios of Z-isomer increase obviously. There has little effect on the E / Z ratio if N,N' - Dimethylpropyl- eneurea (DMPU) is presented as cosolvent. However, E-isomers increase if lithium chloride salt presents in the reaction mixture.

碩士
國立高雄師範大學
生物科技系
101
Spilled chlorinated organic solvents are immiscible in water, and normally present as discrete liquid phases and form nonaqueous phase liquids in aquifers. A dense nonaqueous phase liquid (DNAPL) is a group of organic solvents that are more dense than water. Many of DNAPL contaminated sites have been investigated in Taiwan. Chlorinated solvents pose high cancer risk for workers and residents. Remediations of sites contaminated by DNAPL (especially for chlorinated solvents) are often more difficult than those by heavy metals and petroleum products. Surfactant/cosolvent flushing has been proved to be effective for remediation of chlorinated solvent contaminated sites. Thus, this study used three surfactants (dihexyl sulfosuccinate sodium salt solution (AMA), docasate sodium salt (AOT) and polyoxyethylene (20) sorbitan monooleate (Tween 80)) and mixture of cosolvents (tert-butanol and n-hexanol) to remediate 1,2-dichloroethane, trichloroethylene and dichloromethane contaminated soils. The glass column packed with contaminated soil was flushed with five pore volume of surfactants and cosolvents. A pilot scale of contaminated soils prepared in the laboratory was used to evaluate the removal efficiency of surfactant/cosolvent flushing. Removal efficiency of DNAPL by AOT, Tween 80 and AMA was evaluated. The results indicated that removal efficiency of 1,2-dichloroethane contaminated soil by AOT, Tween 80 and AMA were 14.8%、24.8% and 26.4%, respectively. In the second phase, DNAPL contaminated soil was flushed by AMA and mixed solvent (tert-butanol and n-hexanol) respectively. The results indicated that AMA demonstrating the best removal efficiency of DCM (i.e., 28.5%) at newly contaminated site and 14.6% for aging TCE contaminated site. Newly DNAPL contaminated soil by cosolvent flushing illustrated complete removal of TCE. For aging TCE—contaminated soil, the removal efficiency was 21.6%. The results of this study provided applicable information for remediation of DNAPL contaminated sites.

碩士
國立中央大學
化學工程與材料工程研究所
98
I have systematically studied the morphology and orientation of microstructures in thin films of an asymmetric poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer after the thin films were subjected to solvent annealing in various vapors of nonpolar/polar cosolvents. In the first part of the thesis, I dissolved PS-b-PEO into the four solvents: toluene, benzene, tetrahydrofuran and chloroform. Each of the four solvents has a different evaporation rate. Therefore, I investigated the effect of the evaporation rate on the microphase-separated microdomains and their spatial ordering. Toluene has the slowest solvent rate. As a result, the evaporation of toluene led to hexagonal arrays of cylinders with a perpendicular orientation. On the other hand, I prepared thin films by drop casting and spin coating. It was found that drop casting couldn’t yield uniform thin films due to the coffee ring effect and that spin coating couldn’t generate microstructures with long-range ordering. Therefore, I used another coating approach, dip-coating, to prepare thin films instead. The low withdrawing rate (0.5 mm/s) induced to cylinders with a perpendicular orientation, and the high withdrawing rate (1.25 mm/s) induced to cylinders with a parallel orientation. In the second part of the thesis, I studied the morphologies in thin films after those films were subjected to solvent annealing in various solvent vapors (in mixed vapors of nonpolar/polar cosolvents). The various polar solvents in the mixed vapors were water, methanol, ethanol, 1-propanol, 1-butanol and 1-hexanol whereas the nonpolar solvent was toluene. PS-b-PEO thin films were first deposited on SiOx/Si by dip-coating at 1 mm/s from a 2 wt% toluene solution. I successfully fabricated the long range hexagonal arrays of perpendicularly-oriented cylinders upon solvent annealing thin films in the toluene/ethanol vapor of the volumetric fraction of 95/5. In addition, controling the mixed ratio of nonpolar/polar cosolvents led to complicated microphase-separated morphologies, such as the Fddd structure in the thin film with exposure to the toluene/ethanol vapor of 60/40 and the coexistence of double-gyroids and cylinders in the thin film with solvent annealing in the toluene /1-propanol vapor of the fraction of 85/15.

碩士
淡江大學
化學工程學系
90
This research studied the preparation and characterization of PMMA/PVAc Composite Membrane. Formation of blending 2 kind of Polymethyl methacrylate (PMMA) and Polyvinyl acrylate (PVAc) material and into porous membranes will be investigated in order to improve the synthesis process of commercial PMMA membranes, which suffers from the drawbacks of having to use an IPA content precipitation bath. Membranes will be prepared using the immersion-precipitation method, with IPA and H2O as the cosolvent. The research take use of FTIR、SEM to investigate the interface compatibility, Using SEM、 Tensile Strength、 Wettability to measure the membrane structure,and requires the Particle Sizer to investigate .

博士
台北醫學院
教育心理與輔導學系
86
The purpose of this study was focused on the model drug papaverine HCl for erectical dysfuction by intracavernous injection on clinical , to explore that possibility of topical transdermal administration. The influence of the in vitro percutaneous penetration of the salt and free forms of model drug were examined on two cosolvent series systems, consist of (water, ethanol and propylene glycol (PG)), and (water, ethanol and PEG 400) by simplex lattice experimental design. In addition, the solubility, flux and permeation coefficient through nude mice skin of the drug were caculated and was quantitatively analysized interaction among water, ethanol, PG, PEG 400, cosolvently, by statistical parameters by DESIGN-EXPERT. The results have shown that ethanol effective enhance on series dosage forms of both salt and free types . Among series dosage forms, 10%-20% of propylene glycol had synerigic effect with ethanol up to 30%. On the other hand, in PEG 400 series, although had increment ability by ethanol, the total enhance ability did observe. This was indicate that the addition of PEG decreased the permeability coefficient and increase the partition coefficient of drug in vehicle of water-ethanol-PEG 400 system, to slow the diffusion of the drug into skin. Furthermore using regular solution theory and the cohesion parameter concept, it could explain that partition (Km) and the permeability coefficients (Kp) have directly relation. In order to increase solubility of drug in dosage form, different prescription of salt and free forms of drug were adding by non-ionic Pluronic F127 surfactant and ionic Carbopol 934. The results appeared that only free form of drug in ionic Carbopol gel have enhancement around 1-3 times. The composition of water-ethanol-PG (40/30/30) have most potential enhancement for impotence treatment by tansdermal delivery.