Dissertations / Theses on the topic 'Cosolvency'
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Burnam, Sarah R. "The effect of ethanol cosolvency on benzene /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1456296021&sid=9&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full textFetterolf, Glendon J. IV. "Characterization of a Creosote-Contaminated Tie Yard Site and the Effects of Phytoremediation." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36802.
Full textMaster of Science
He, Yan. "Solubilization of Poorly Water-Soluble Drugs: Theory and Applications." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1096%5F1%5Fm.pdf&type=application/pdf.
Full textBORGES, ANDREA FERREIRA. "NUMERICAL MODELLING OF TWO-PHASE FLOW AND TRANSPORT IN POROUS MEDIA WITH MASS TRANSFER AND COSOLVENCY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5960@1.
Full textNeste 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.
Melo, Polyanne Nunes de. "Prepara??o e caracteriza??o de complexos multicomponentes contendo ciclodextrinas e benznidazol." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13488.
Full textConselho 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
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Gunold, Roman. "Silikonstab-Passivsammler für hydrophobe Organika." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-198422.
Full textZhao, Luwei. "Stabilization of eptifibatide by cosolvents." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/289163.
Full textYao, Jian. "NMR Study of Neurophysin Dimer Dissociation by Cosolvents." PDXScholar, 1996. https://pdxscholar.library.pdx.edu/open_access_etds/5209.
Full textMorris, Kenneth Robert 1951. "THE SOLUBILITY OF HYDROPHOBIC POLLUTANTS IN WATER-COSOLVENT MIXTURES." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276659.
Full textJangher, Abdulhakim Ali. "Temperature and cosolvent effects of polymer conformations in solution." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/55113/.
Full textPaan, Padma. "Effect of alcohol cosolvents on the aqueous solubility of toxaphene." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011373.
Full textYuan, Yanhui. "Specific interactions in polymer + CO₂ + cosolvent systems: experiment and modeling." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37139.
Full textABRAMOWITZ, ROBERT. "ESTIMATION OF THE MELTING POINT OF RIGID ORGANIC COMPOUNDS (COSOLVENT, NAPHTHALENE)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183935.
Full textChawla, Monica Kapoor 1950. "THE ROLE OF SEVERAL DRUGS AND COSOLVENTS ON INFUSION RELATED PHLEBITIS (THERMOGRAPHY)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276915.
Full textSuryanarayanan, Sowmya. "Metalloporphyrin catalyzed degradation of PCE / effects of reductants, buffers and cosolvent concentration." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202500559/.
Full textMitchell, Nathan. "Eyring Activation Energy Analysis of Acetic Anhydride Hydrolysis in Acetonitrile Cosolvent Systems." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3430.
Full textMiyako, Yasuhiro. "Theoretical approach for solubility enhancement of poorly soluble drugs with organic cosolvent." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/131925.
Full textRamasubramanian, Lavanya. "Cosolvent effects on the reductive dechlorination of tetrachloroethylene catalyzed by iron tetraphenyl porphyrin chloride." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202417223/.
Full textFerreira, Sayonara Brederode. "Estudos laboratoriais para avaliação do ootencial de contaminação de água e de solo por gasolina oxigenada." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-11122002-134550/.
Full textIn 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.
Vyalov, Ivan. "Molecular dynamics simulation of dissolution of cellulose in supercritical fluids and mixtures of cosolvents/supercritical fluids." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10178/document.
Full textCellulose 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
Wallraf, Anne-Maria [Verfasser], Ulrich [Akademischer Betreuer] Schwaneberg, and Lars Mathias [Akademischer Betreuer] Blank. "Protein engineering of laccase for improved resistance towards cosolvents / Anne-Maria Wallraf ; Ulrich Schwaneberg, Lars Mathias Blank." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1181108950/34.
Full textOlowoyo, Samson. "Kinetics and Activation Energy Parameters for Hydrolysis of Acetic Anhydride in a Water-Acetone Cosolvent System." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3409.
Full textHassan, Sami Kadhim. "Investigation of Sugar/Polyols as Weakly Interacting Cosolvents and their Influence on Hardening of High-Protein Nutrition Bars." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4512.
Full textMurakami, Shota. "Theoretical Prediction of Changes in Protein Structural Stability upon Cosolvent or Salt Addition and Amino-acid Mutation." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225706.
Full textAjaj, Yathrib [Verfasser], Hermann [Gutachter] Weingärtner, and Christian [Gutachter] Herrmann. "Dynamics and thermodynamics of protein folding and interactions in water-cosolvent systems / Yathrib Ajaj ; Gutachter: Hermann Weingärtner, Christian Herrmann." Bochum : Ruhr-Universität Bochum, 2012. http://d-nb.info/1131354575/34.
Full textGrimes, Matthew, Paul Myrdal, and Poonam Sheth. "Cosolvent Effect on Droplet Evaporation Time, Aerodynamic Particle Size Distribution, and Differential Throat Deposition for Pressurized Metered Dose Inhalers." The University of Arizona, 2015. http://hdl.handle.net/10150/614123.
Full textObjectives: 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.
Elie, Marc. "Use of an Activated Magnesium/cosolvent System for the Desorption and Degradation of Polycyclic Aromatic Hydrocarbons and Their Oxygenated Derivatives in Contaminated Soils." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5196.
Full textPh.D.
Doctorate
Chemistry
Sciences
Chemistry
Zêzere, Bruno Miguel Martins. "Diffusivities of bioactive compounds in supercritical mixtures and expanded solvents." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22524.
Full textNas 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.
Santos, Kátia Andressa. "Estudo dos processos de extração do óleo de candeia (Eremanthus erythropappus) com fluidos pressurizados e solvente assistido por ultrassom." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3579.
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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.
Collins, Karl Daniel. "The development and application of radical and anionic cyclisations mediated by samarium(II) diodide and protic co-solvents." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/the-development-and-application-of-radical-and-anionic-cyclisations-mediated-by-samariumii-diodide-and-protic-cosolvents(0e807a8c-d40f-45bb-8d83-26e79ebe9388).html.
Full textSoares, Belinda Isabel Gomes. "Development of an innovative technology for wood delignification with eutectic solvents." Doctoral thesis, 2019. http://hdl.handle.net/10773/30287.
Full textEste 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
Jones, Adam Terrell. "Cosolvent effects in polymer-solvent systems." 2007. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1959/index.html.
Full textGunold, Roman. "Silikonstab-Passivsammler für hydrophobe Organika: Aufnahmekinetik, Verteilungskoeffizienten, Modellierung und Freiland-Kalibrierung." Doctoral thesis, 2015. https://tubaf.qucosa.de/id/qucosa%3A23025.
Full textJien, Chih-Hsiang, and 簡智翔. "Solubility of β-carotene in supercritical CO2 with cosolvent." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/59680765387941986163.
Full text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.
Ting, Yi-Hsiu, and 丁翊修. "Predict the solubility of solid compounds in SCCO2 with cosolvents." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/70155737721070390784.
Full text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 andHm 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.
Lee, Maeng Eun [Verfasser]. "Atomistic simulations of cosolvent-water mixtures : force field development and application to cosolvent effects on nonpolar solubility and hydrophobic interactions / Maeng Eun Lee." 2006. http://d-nb.info/982382456/34.
Full textCheng, Charles, and 鄭承熙. "Solubility of Disperse Dyes in Supercritical Carbon Dioxide : Cosolvent Effect." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/45850106840359658038.
Full text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.
Hsieh, Hsin Chan, and 謝欣展. "Methanol-Ethanol Cosolvent-Induced Crack Healing in Poly(methyl methacrylate)." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/39309025241463086668.
Full text何峻嘉. "Solubility of Disperse Dyes in Supercritical Fluids with or without Cosolvent." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/38906460937652966076.
Full text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.
Chen, Chun-Chao, and 陳俊超. "Study of Cosolvent Techniques in Manufacturing Large Area Flexible Organic Photovoltaic Modules." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/75891388397841079186.
Full text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.
Yeh, Shao-Jen, and 葉紹任. "Cosolvent Effects on Stability of Catanionic Vesicles Formed by Ion Pair Amphiphiles." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/94414261875762003133.
Full text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.
tsui-yin, Huang, and 黃翠瑩. "Evaluation of organic contaminants removal in contaminated soils by cosolvent flushing technique." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/41449050723665529571.
Full text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.
Shen, Xiu-Ci, and 沈繡慈. "Cosolvent and Metal Ion Effects in the Synthesis of Stereoselective Vinyl Fluorine Compounds." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/28973840879021311501.
Full text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.
Huang, Chiung-Yi, and 黃瓊儀. "Evaluation of DNAPL Removal in Contaminated Soils by Surfactant and Cosolvent Flushing Technique." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/16369154949640083855.
Full text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.
Hsu, Shih-Ping, and 徐士平. "Controls over Microdomain in Diblock Copolymer Thin Films by Polar/Nonpolar Cosolvent Annealing." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53006056248560718245.
Full text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.
Huag, Han-Shiang, and 洪漢祥. "Preparation of Poly(methyl methacrylate) / Poly(vinyl acetate) Composite Membrane by Cosolvent System." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/83206710037458199869.
Full text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 .
Sathish, H. A. "Effect of cosolvents and denaturants on structure function relationship of Papain from carica Papaya." Thesis, 2000. http://hdl.handle.net/2009/1416.
Full textTata, Shahnaz Sorab. "Influence of propylene glycol and ethanol cosolvents on deposition of minoxidil into the skin." 1995. http://catalog.hathitrust.org/api/volumes/oclc/68798085.html.
Full textYuh-horng, Kao, and 高聿虹. "The evaluation of affection of the drug in cosolvent gel system penetrate through epidermis." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/98101508555430441758.
Full text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.
Constantinescu, Aruxandei Diana [Verfasser]. "Patterns of protein stability and interactions in water-cosolvent systems / vorgelegt von Diana Constantinescu Aruxandei." 2010. http://d-nb.info/1007596546/34.
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