Dissertationen: „Solvent-solvent“

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Chun-Te, Lin Justin. „Organic solvent nanofiltration membrane cascades for solvent exchange and purification“. Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/11977.

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2

Męcfel-Marczewski, Joanna. „Self Incompatible Solvent“. Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201001195.

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In dieser Arbeit wird das neue Prinzip der „Selbstinkompatiblen Lösungsmittel“ vorgestellt. Es wird theoretisch abgeleitet, dass eine Mischung aus zwei Substanzen mit ungünstigen Wechselwirkungen bereitwillig eine weitere Substanz aufnehmen sollte, die diese ungünstigen Wechselwirkungen durch Verdünnen vermindert. Dies sollte umso stärker ausgeprägt sein, je ungünstiger die Wechselwirkungen zwischen den beiden ersten Substanzen sind. Da sich jedoch Substanzen mit sehr ungünstigen Wechselwirkungen physikalisch nicht mischen, entstand die Idee, diese Substanzen durch eine kovalente Bindung aneinander zu binden. Ein solches Molekül, das aus zwei inkompatiblen Hälften besteht, wird im Folgendem Selbstinkompatibles Lösungsmittel genannt. Die in dieser Arbeit gewählten Substanzen zeigen mäßige Inkompatibilität, deshalb ist ein Vergleich zwischen einfachen physikalischen Mischungen und kovalent verknüpften Molekülhälften noch möglich. Dieses Prinzip wird für binäre und ternäre Mischungen quantitativ berechnet und experimentell in drei Serien von Experimenten bestätigt: i) unter Verwendung von Lösungskalorimetrie und Bestimmung der Wechselwirkungsparameter zwischen Komponente 3 und einer bereits hergestellt physikalischen binären Mischung aus Komponente 1 und 2, ii) unter Verwendung von Lösungskalorimetrie und Bestimmung der Wechselwirkungsparameter zwischen Komponente 3 und den selbstinkompatiblen Losungsmitteln, die den in (i) gewählten Mischungen entsprechen und iii) aus der Sättigungslöslichkeit der Komponente 3 in den entsprechenden selbstinkompatiblen Lösungsmitteln. In diesen drei verschiedenen Messserien wird stets der gleichen Trend beobachtet: Die Selbstinkompatibilität eines Lösungsmittels begünstigt den Lösevorgang
In this thesis a new principle of Self Incompatible Solvent is introduced. It is shown theoretically that a preexisting mixture of two substances (compound 1 and 2) with unfavorable interactions will readily dissolve a third compound because it diminishes the unfavorable interaction between the compound 1 and 2 by dilution. This behavior should be the stronger the more unfavorable the interactions between compound 1 and 2 are. However, substances with strong unfavorable interactions will not mix. Therefore the idea pursued here is to enforce the desired preexisting mixture for example by linking compound 1 covalently to compound 2. Such a molecule that is composed of two incompatible parts is called Self Incompatible Solvent in this work. In this thesis examples of incompatible compounds that show moderate incompatibility are chosen, therefore it was possible to do a comparison between simple physical mixtures and covalently linked incompatible molecules. The theoretical prediction of the theory is compared with experiments. This principle is calculated quantitatively for binary and ternary mixtures and compared with the experimental results in three distinct series of experiments: i) by using solution calorimetry and calculation of the interaction parameters between compounds 3 and the preexisting binary mixture of compound 1 and 2, ii) by using solution calorimetry and calculation of the interaction parameters between compound 3 and the Self Incompatible Solvent that correspond to the mixtures used in (i) and iii) from the saturation solubility of compound 3 in the Self Incompatible Solvent. The results obtained from the theoretical prediction and these obtained from the three different series of experiments show the same trend: the self incompatibility of the solvent improves the dissolution process

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3

Rodarte, Alma Isabel Marín. „Predispersed solvent extraction“. Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45173.

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A new solvent extraction method has been developed for the extraction of metal and organic ions from very dilute aqueous solutions. The new method, which has been named Predispersed Solvent Extraction (POSE), is based on the principle that 1 there is no need to comminute both phases. All that is necessary is to comminute the solvent phase prior to contacting it with the feed. This is done by converting the solvent into aphrons, which are micron-sized globules encapsulated in a soapy film. Since the aphrons are so small, it takes a long time for the solvent to rise to the surface under the influence of gravity alone. Therefore, the separation is expedited by piggy-back flotation of the aphrons on specially prepared gas bubbles, which are somewhat larger than aphrons and are called colloidal gas aphrons (CGA).

Copper, uranium and chromium ions, and alizarin yellow were extracted from very dilute aqueous solutions using PDSE. Tests were performed in a vertical glass column in both batch and continuous modes, and in a continuous horizontal trough. The new solvent extraction procedure worked very efficiently and very quickly under laboratory conditions. Higher than 99% extraction was achieved in many of the tests performed.

Master of Science

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Xu, Zhuang. „PARTITIONING OF SOLVENT MOLECULES SURROUNGDING POLYMER CHIANS IN SOLVENT-SHIFTING PROCESS“. University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1555690517286259.

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5

Wang, Nan. „CO2 Separation - from Aqueous Amine Solvent to Ionic Liquid-based solvent“. Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84244.

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6

Tarkan, Haci Mustafa. „Air-assisted solvent extraction“. Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102735.

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Air-Assisted Solvent Extraction (AASX) is a novel concept that uses a solvent-coated bubble to contact the organic and aqueous phases. The advantages over conventional solvent extraction (SX) are high solvent to aqueous contact area with reduced solvent volume and ease of phase separation due to the buoyancy imparted by the air core. This opens the way to treat dilute solutions (<1 g/L), such as effluents.
The novel contribution in this thesis is the production of solvent-coated bubbles by exploiting foaming properties of kerosene-based solvents.
The basic set-up is a chamber to generate foam which is injected through a capillary (orifice diameter 2.5 mm) to produce solvent-coated bubbles (ca. 4.4 mm) which release into the aqueous phase. This generates a solvent specific surface area of ca. 3000 cm-1, equivalent to solvent droplets of ca. 20 mum. Demonstrating the process on dilute Cu solutions (down to 25 mg/L), high aqueous/organic ratios (ca. 75:1) and extractions are achieved. The solvent readily disengages to accumulate at the surface of the aqueous solution.
The LIX family of extractants imparts some foaming to kerosene based solvents but D2EHPA does not. An extensive experimental program determined that 1.5 ppm silicone oil provided the necessary foaming action without affecting extraction or stripping efficiency, greatly expanding the range of solvents that can be used in AASX.
To complement the foam study, films on bubbles blown in solvent were examined by interferometry (film thickness) and infra-red spectroscopy (film composition). A "bound" solvent layer was identified with an initial thickness of ca. 2 - 4 mum, comparable to that determined indirectly (by counting bubbles in an AASX trial and measuring solvent consumption). The film composition appeared to be independent of film thickness as it decreased with time.
As a start to scaling up, the single bubble generation system was adapted by installing up to 8 horizontal capillaries. The bubbles generated were ca. 3.4 mm. Trials showed the multi-bubble set up was a simple replication of the individual bubble case. Preliminary analysis of kinetic data shows a fit to a first-order model.

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Brogan, Alex P. S. „Solvent-free liquid proteins“. Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573415.

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The work presented in this thesis represents the first investigation into the structure, function, and material properties of solvent-free liquids of globular proteins. Using myoglobin as an archetypal system, it has been shown that solvent-free liquid proteins can be synthesized through the engineering of protein surfaces with an organic corona made from polymer surfactants. These novel materials have been shown to be stoichiometric constructs of protein and surfactant, with respect to charge, that once lyophilized form liquid-like materials with unique thermal properties and very low water contents. The generality of the synthetic procedure was tested with the formation of solvent-free liquid proteins with a variety of surfactants. The result of which was that for myoglobin, there was a surfactant molecular weight limit of c. 700 mg.mL-1 with respect to the constructs that possessed liquid phases. The suggestion of which was that the corona had to extended from the surface of the protein enough to satisfy the interparticle interactions required to yield an accessible liquid state. Spectroscopic measurements were used to assess the secondary structure of proteins in the solvent-free liquid state. UV/Vis spectroscopy showed that the prosthetic heme of myoglobin (and hemoglobin) was retained in a structurally conserved environment, and CD spectroscopy showed the retention of a significant amount of secondary structure. These studies were extended to show that in the absence of water, proteins retained the ability to thermally denature and subsequently refold. This proceeded with extraordinary thermal stability, with solvent-free liquid myoglobin exhibiting a half denaturation temperature of c. 160 QC. With the persistence of secondary structure in solvent-free liquid proteins, the function of myoglobin was also investigated. It has been shown that in the absence of water, oxygen binding was achievable up to 125 QC.

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Sackin, Robert. „Solvent ingress in polymers“. Thesis, University of Surrey, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326197.

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9

Bajpayee, Anurag. „Directional solvent extraction desalination“. Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78539.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.
"September 2012." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 131-137).
World water supply is struggling to meet demand. Production of fresh water from the oceans could supply this demand almost indefinitely. As global energy consumption continues to increase, water and energy resources are getting closely intertwined, especially with regards to the water consumption and contamination in the unconventional oil and gas industry. Development of effective, affordable desalination and water treatment technologies is thus vital to meeting future demand, maintaining economic development, enabling continued growth of energy resources, and preventing regional and international conflict. We have developed a new low temperature, membrane-free desalination technology using directional solvents capable of extracting pure water from a contaminated solution without themselves dissolving in the recovered water. This method dissolves the water into a directional solvent by increasing its temperature, rejects salts and other contaminants, then recovers pure water by cooling back to ambient temperature, and re-uses the solvent. The directional solvents used here include soybean oil, hexanoic acid, decanoic acid, and octanoic acid with the last two observed to be the most effective. These fatty acids exhibit the required characteristics by having a hydrophilic carboxylic acid end which bonds to water molecules but the hydrophobic chain prevents the dissolution of water soluble salts as well the dissolution of the solvent in water. Directional solvent extraction may be considered a molecular-level desalination approach. Directional Solvent Extraction circumvents the need for membranes, uses simple, inexpensive machinery, and by operating at low temperatures offers the potential for using waste heat. This technique also lends itself well to treatment of feed waters over a wide range of total dissolved solids (TDS) levels and is one of the very few known techniques to extract water from saturated brines. We demonstrate >95% salt rejection for seawater TDS concentrations (35,000 ppm) as well as for oilfield produced water TDS concentrations (>100,000 ppm) and saturated brines (300,000 ppm) through a benchtop batch process, and recovery ratios as high as 85% for feed TDS of 35,000 ppm through a multi-stage batch process. We have also designed, constructed, and demonstrated a semi-continuous process prototype. The energy and economic analysis suggests that this technique could become an effective, affordable method for seawater desalination and for treatment of produced water from unconventional oil and gas extraction.
by Anurag Bajpayee.
Ph.D.

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TRUJILLO, REBOLLO ANDRES. „SOLVENT EXTRACTION OF MOLYBDENUM“. Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184009.

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The equilibrium and the kinetics of the reaction of Mo (VI) with 8-hydroxyquinoline; 8-hydroxyquinaldine; KELEX 100; LIX63; and LIX65N were studied by solvent extraction. From the equilibrium studies it was concluded that in weakly acidic solution (pH 5 to 6) the overall extraction reaction is (UNFORMATTED TABLE FOLLOWS) MoO₄²⁻ + 2H⁺ + 2HL(o) ↔ (K(ex)) MoO₂L ₂(o) + 2H₂O (TABLE ENDS) where HL is the monoprotic bidentate ligand, "(o)" refers to the organic phase, and K(,ex) is the extraction constant. It was concluded that the complexation reaction requires four protons to convert molybdate into molybdenyl. The extractions constants for LIX63 and 8-hydroxyquinaldine, corrected for the side reaction of the ligand and metal, are 10¹⁶·⁴³ and 10¹⁴·⁴⁰, respectively. In the case of LIX65N, the plot of log(D) vs pH has a maximum at pH 1.0, which was explained qualitatively in terms of protonation of the ligand and molybdic acid at low pH. The extraction constant for the reaction of molybdic acid and the neutral ligand was estimated to be 100,000. The kinetics of extraction Mo (VI) with LIX63, 8-hydroxyquinoline, 8-hydroxyquinaldine, and Kelex 100 were studied in this work. In all cases, except 8-hydroxyquinoline, the rate-determining step of the reaction involves the formation of a 1:1 complex between the neutral ligand and several Mo(VI) species differing in the degree of protonation. The rate-determining step for the reaction of Mo(VI) with 8-hydroxyquinoline involves the formation of a 1:2 complex. The rate constant for the reaction of HMoO₄ with 8-hydroxyquinaldine is four orders of magnitude smaller than the corresponding value reported in the literature for 8-hydroxyquinoline. The slower reaction with 8-hydroxyquinaldine was attributed to the presence of the methyl group next to the nitrogen atom of the ligand which hinders its binding with molybdenum in the rate determining step of the reaction.

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Odiase, Isaac Uhunomah. „An anti-solvent/solvent mixture approach for pharmaceutical cocrystals and salt at pilot-scale“. Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10566/.

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Cocrystals have generated a lot of interest due their ability to influence: physiochemical properties, optical properties etc. These properties are important in the pharmaceutical and food industry. In this thesis, the scale up of cocrystal synthesis is studied using a novel slurry cocrystallisation approach involving an anti-solvent and solvent mixture. The anti-solvent composition is typically > 97 %, with the solvent comprising the rest. This counter-intuitive approach resulted in > 95 % caffeine-oxalic acid cocrystal yield in less than 2 hrs. The mixed anti-solvent/solvent approach was applied successfully to four other cocrystal systems and a salt. The level of caffeine-oxalic acid cocrystal yield observed varied with the solvent used in the mixture. Using statistical analysis, it was shown that the hydrogen bonding Hansen solubility parameter (δH) of the solvent and oxalic acid solubility were the two most important factors for increasing cocrystal yield. The parameter Ra/(Oxalic acid) , however, showed even better correlation (94.2 %) with caffeine-oxalic acid cocrystal yield than both δH (78 %) and oxalic acid solubility (88 %). Ra is the Hansen solubility distance between the solvent and the coformer (oxalic acid) and includes all three Hansen solubility parameters (δD, δP, δH). Four new cocrystals (A-D) of 2-aminopyrimdine-glutaric acid were crystallised from three different solvents and their crystal structures reported. Two of them (A and B) are 1:1 polymorphs. The glutaric acid molecule in A has a linear conformation but it is twisted in B. Variable temperature PXRD analysis indicates that A and B are monotropic polymorphs, with A transforming to B at ≈73C, prior to the melting of B. D is a cocrystal-salt hybrid. D was crystallised from the same solvent as cocrystal B supporting the idea of a cocrystal-salt continuum when both the neutral and ionic forms are present in appreciable concentrations in solution.

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Makowski, Marcin. „Solvent nanofiltration for purifying pharmaceuticals“. Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/29227.

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The projections recently published by the United Nations (UN) suggest that the global population may reach 8.9 billion people by the year 2050. Life expectancy is assumed to rise constantly with no upper limit and by the year 2100 is expected to vary from 66 to 97 years. As the population ages the demand for effective medicines is rising. At the same time the pharmaceutical industry keeps applying pressure to shorten development timelines for new chemical entities, so that new medicines can reach patients much faster. In the development and manufacturing of drugs the purification steps often consume the highest proportion of the processing time and costs. In parallel, there has been a surge in the expectations of patients regarding the purity of the desired pharmaceuticals. There are several processes available for yielding purified product: liquid chromatography, crystallization or distillation among others most of them, however have limitations. Therefore, progress is required in innovative technologies and processes characterized by higher stability, better selectivity and lower energy requirements. Applying membrane technology in the separation and purification of compounds can result in lower operating temperatures being needed, and less harsh conditions required, when compared to other processes. Thus it is of interest for Active Pharmaceutical Ingredient (API) manufacturing. Polymeric membranes are the most widely used for industrial membrane applications. However, an important challenge is to apply the existing polymeric membranes (suitable for aqueous operations) to non-aqueous solutions. Recent progress has led to the development of Organic Solvent Nanofiltration (OSN). OSN utilises solvent-resistant polymeric membranes to selectively retain solutes, and simultaneously allows smaller molecules to pass through the membrane. Nevertheless, ways in which membrane performance impacts the overall purification process have not yet been fully studied. Developing mathematical models of purification processes might help to better understand, and therefore better predict and control, the membrane process. Knowing the importance of a membrane in a filtration process, one should try to identify the areas where new membranes are desired. At the same time, one should try to understand how factors influencing membrane formation will affect membrane's final performance. As a benefit of the research conducted, by the end of this study the knowledge gained should result in the fabrication of membranes with enhanced capabilities.

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Salehpour, Somaieh. „Biodiesel: A green polymerization solvent“. Thesis, University of Ottawa (Canada), 2007. http://hdl.handle.net/10393/27916.

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A number of polymer products are traditionally made using a solution polymerization technique. However, with increased environmental awareness and thus, concerns over the volatile organic content (VOC) associated with various polymer processes, there is an ongoing effort to find alternatives to traditional solvents. In an effort to use cleaner technologies, fatty acid methyl ester (FAME) was used for the first time as a polymerization solvent. Biodiesel or FAME has garnered much attention in recent years as an alternative to diesel fuel. It is environmentally benign and has a low volatility. Because biodiesel is a high boiling solvent, its use can increase productivity by enabling polymerizations at elevated temperatures. This would result in faster reaction rates and thus, shorter reaction times. In the first part of this study, solution polymerizations of four commercially important monomers (i.e., methyl methacrylate (MMA), styrene, butyl acrylate (BA) and vinyl acetate (VAc)) were studied at 60°C using FAME produced from canola oil as a solvent. Reactions were carried out at different solvent concentrations to verify the effect of the FAME on the polymerizations. Chain transfer to solvent rate parameters were obtained using the Mayo method. In addition, the effect of solvent on solution polymerizations of each monomer was investigated. This was suspected to contribute to a change in the lumped kinetic parameter (kp/kt1/2). The collected kinetic experimental data were modeled using a polymerization simulator. In the second part of this thesis, canola-based FAME was used as a high boiling solvent in the solution polymerization of the aforementioned monomers at 120°C. Chain transfer to solvent rate constants were calculated and were employed in a polymerization simulator to predict the polymerization rates and the cumulative average molecular weights of the polymer product. As in the study at 60°C, changes in the lumped kinetic parameter with solvent concentration were incorporated into the free radical polymerization simulator; these changes considerably improved the model predictions. In the third part of the thesis, the effect of FAME produced from different oil feedstocks on polymerization kinetics was investigated for styrene homopolymerizations at 60°C. Soybean oil, and 50% yellow grease-50% canola oil were the feedstocks employed in this study. Experimental results were compared to the runs using canola-based FAME at 60°C. Chain transfer to solvent constants were estimated for each solvent using the Mayo method and no significant difference between the values obtained from polymerization in different FAME was found. On the other hand, dissimilar effects on the rate of polymerization were observed. These were shown to relate to the degree of unsaturation of each FAME type. Model predictions of reaction rates and molecular weights for the investigated systems are also presented.

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Jackson, Linda C. „Neutral solvent pulping product characterization“. Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/11234.

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Tavakolikhaledi, Mohammadreza. „Vanadium : leaching and solvent extraction“. Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46814.

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The fundamental understanding of vanadium hydrometallurgy was developed in three phases: vanadium (V) leaching, vanadium (III) oxidative leaching, and solvent extraction of vanadium (V&IV). In the first section, V₂O₅ leaching was studied in three steps. First, vanadium leaching and solubility of VO₂⁺ at different pH’s and temperatures were investigated in sulfuric acid. Secondly, the kinetics of vanadium leaching in pH 5 and pH 8 solutions, and the reductive leaching of vanadium pentoxide using sodium sulfite were studied. It was shown that the kinetics of acid leaching is rapid but suffers from low solubility of VO₂⁺ in solution. Thirdly, the shrinking sphere model was employed to analyze the kinetics of reductive leaching. In the second step, V₂O₃ oxidative leaching was studied from 30°C to 90°C in sulfuric acid. This study has also been done in three different sections. First, the kinetics of oxidative leaching using oxygen was investigated. It was shown that this oxidative leaching is chemical reaction rate controlled with an activation energy of 69 kJ/mol. In the next step, it was shown that the presence of ferric enhanced kinetics significantly. Finally, oxidative leaching using a constant ferric-ferrous ratio from 1 to 300 was studied. The addition of KMnO₄ solution to the leach reactor was found to be a suitable oxidant for controlling solution potential. The oxidation rate using the constant ferric-ferrous ratio was very sensitive to temperature, with a large activation energy (38 kJ/mol) and the rate was proportional to the Fe(III)/Fe(II) concentration to the power of 0.47. In the third part, purification of synthetic vanadium-containing solutions using the solvent extraction technique was investigated. Various solvent extractants have been tested for vanadium recovery from acid leachates. One of the biggest problems for purification of the vanadium solution is iron separation. Therefore, this research assesses selectivity of vanadium over iron. The extraction of vanadium (V&IV), iron (III&II) with phosphinic acid (CYANEX 272), phosphonic acid (IONQUEST 801), phosphoric acid (D2EHPA) and phosphine oxide (CYANEX 923) extractants is reported. In addition, the extraction reactions for vanadium (V) and (IV) extraction using CYANEX 923 and D2EHPA were also studied.

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Traynor, Matthew John. „Dermal absorption of solvent mixtures“. Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427345.

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Al-Murshedi, Azhar Yaseen Muhi. „Deep eutectic solvent-water mixtures“. Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/42799.

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

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Bolielyi, O. C., T. I. Obushenko und N. M. Tolstopalova. „Solvent sublation of сopper ions“. Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/52832.

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Heavy metals belong to the most common and dangerous pollutants. Thus, the development of new improved and economical methods for metallic ions removing appears to be actual problem for researchers and technologists.

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Tippmann, Eric M. „Studies of carbene-solvent interactions“. Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1070405724.

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Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xxviii, 310 p.; also includes graphics (some col.) Includes bibliographical references (p. 181-183). Available online via OhioLINK's ETD Center

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Muangthong-On/Trairat. „Effect of Solvent on the Degradative Solvent Extraction of Low Rank Coal and Examination of Propensity to Spontaneous Heating of the Solvent Treated Coal and Residue“. Kyoto University, 2009. http://hdl.handle.net/2433/227654.

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Muangthong-On, Trairat. „Effect of Solvent on the Degradative Solvent Extraction of Low Rank Coal and Examination of Propensity to Spontaneous Heating of the Solvent Treated Coal and Residue“. Doctoral thesis, Kyoto University, 2017. http://hdl.handle.net/2433/227654.

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京都大学
0048
新制・課程博士
博士(エネルギー科学)
甲第20731号
エネ博第359号
新制||エネ||70(附属図書館)
京都大学大学院エネルギー科学研究科エネルギー応用科学専攻
(主査)教授大垣英明, 教授松田一成, 教授河瀬元明
学位規則第4条第1項該当
Doctor of Energy Science
Kyoto University
DFAM

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Agrawal, Swati. „Investigation and Optimization of a Solvent / Anti-Solvent Crystallization Process for the Production of Inhalation Particles“. VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2244.

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Dry powder inhalers (DPIs) are commonly used to deliver drugs to the lungs. The drug particles used in these DPIs should possess a number of key properties. These include an aerodynamic particle size < 5μm and particle crystallinity for long term formulation stability. The conventionally used micronization technique to produce inhalation particles offers limited opportunities to control and optimize the particle characteristics. It is also known to induce crystalline disorder in the particles leading to formulation instability. Hence, this research project investigates and optimizes a solvent/anti-solvent crystallization process capable of directly yielding inhalation particles using albuterol sulfate (AS) as a model drug. Further, the feasibility of the process to produce combination particles of AS and ipratropium bromide monohydrate (IB) in predictable proportions and in a size suitable for inhalation is also investigated. The solvent / anti-solvent systems employed were water / ethyl acetate (EA) and water / isopropanol (IPA). Investigation and optimization of the crystallization variables with the water / EA system revealed that particle crystallinity was significantly influenced by an interaction between the drug solution / anti-solvent ratio (Ra ratio), stirring speed and crystal maturation time. Inducing a temperature difference between the drug solution and anti-solvent (Tdrug solution > Tanti-solvent) resulted in smaller particles being formed at a positive temperature difference of 65°C. IPA was shown to be the optimum anti-solvent for producing AS particles (IPA-AS) in a size range suitable for inhalation. In vitro aerosol performance of these IPA-AS particles was found to be superior compared to the conventionally used micronized particles when aerosolized from the Novolizer®. The solvent / anti-solvent systems investigated and optimized for combination particles were water / EA, water / IPA, and water / IPA:EA 1:10 (w/w). IPA was found to be the optimum anti-solvent for producing combination particles of AS and IB with the smallest size. These combination particles showed uniform co-deposition during in vitro aerosol performance testing from the Novolizer®. Pilot molecular modeling studies in conjunction with the analysis of particle interactions using HINT provided an improved understanding of the possible interactions between AS and IB within a combination particle matrix.

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Thanthiriwatte, Kanchana Sahan. „Solvent methods in coupled-cluster theory“. Diss., Mississippi State : Mississippi State University, 2009. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04032009-090013/.

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24

Wang, Xuewei. „Alternative reactive solvent for ABB products“. Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68671.

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The epoxy resin mixture is used for wet filament winding load carrying and electrically insulating tubes for high voltage applications. The cured tubes are key parts of the final products which are subject to qualification. The safe function of the products generally depends on low moisture content. Visual inspection is also an important part of the quality inspection which requires some degree of transparency of the cured tubes. To prepare for future material modifications ABB wishes to evaluate the curing characteristics of some recently developed epoxy/hardener systems. The epoxy resin with the formulation E1/H1 is used as reference. Another type of base epoxy resin E2 and toughened epoxy resin E1 (E1T) are included in the study. Three alternative hardeners H2, H3, and H4 were evaluated. This project is to evaluate different alternative epoxy resin formulations that are promising to be used in the ABB products in the future. These alternative epoxy resin formulations and the reference epoxy resin with the formation E1/H1 were prepared to be compared and evaluated in terms of thermal properties, i.e., glass temperature (Tg), the heat of curing and color of cured epoxy resins. The epoxy resins with alternative formulations which shown relative high Tg values were selected to carry out other analysis, ie., mixing ration optimization, the influence of dissolved water on Tg values, degree of curing and water absorption behavior.

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25

Faass, George Steven. „Development of a solvent pulping process“. Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/10931.

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26

Suriyachat, Duangkamol. „Zirconium solvent extraction using organophosphorus compounds“. Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60718.

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This study compares zirconium extraction from hydrochloric acid solutions using either Cyanex 923 or Cyanex 925 in kerosene. While both are mixtures of trialkyl phosphine oxides, the trialkyl groups in the former have straight chains, while those in the latter have branched chains.
The major variables studied were hydrochloric acid, extractant and zirconium concentrations, and phase ratio. With both reagents, zirconium is extracted rapidly. Extraction increases with increasing hydrochloric acid concentration, and zirconium is loaded as its neutral tetrachloride complex by a solvation reaction. The loaded zirconium forms a di-solvate, except at high excess extractant concentrations, where solvation numbers greater than 2 are found. At a constant total chloride concentration, the zirconium extraction level is maintained if hydrochloric acid is partially replaced by lithium chloride, provided sufficient hydrochloric acid is retained to prevent zirconium hydrolysis. Distribution coefficients decease with increasing zirconium concentration, suggesting that polymerization occurs in the aqueous phase.
For given conditions, zirconium extraction into Cyanex 923 is higher than for Cyanex 925. However, loading selectivity for zirconium over other metals has not been studied. A few preliminary experiments have shown that aqueous solutions of ammonium carbonate are potential stripping agents.

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27

Labrèche, France P. „Occupational solvent exposure and mental disorders“. Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74252.

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A case-referent study was designed to investigate the relationship between occupational solvent exposure and mental disorders. New cases of mental disorder (males, 40 to 69 years old), were individually matched for age and date of admission to hospital patients and neighbors. An occupational history was obtained from 91.7% of the sample (1143 subjects, or 381 'trios'), during a telephone interview or by mail.
No increased risk of mental disorders was found among subjects exposed to moderate levels of solvents, but the risk was elevated--though not to a statistically significant degree--at exposure to high levels. When diagnoses were divided into psychotic (ICD-9 codes 290-299) and non-psychotic (ICD-9 codes 300-316), the latter group presented an increased risk with exposure to high levels of solvents (odds ratio = 2.43, 90% C.I. = 1.16-5.08). No systematic exposure-response relationship was demonstrated, although there was a suggestion of increased risk of mental disorders among subjects exposed to high levels for 5 to 9 years.
Various aspects of referent selection--with a specific comparison of hospital and population referents--were also examined as a methodological issue of case-referent studies.

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28

Yang, Fan 1980. „Solvent mediated interaction between hydrophobic spheres“. Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84087.

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We develop a coarse grained methodology to study solvent mediated interactions between two or more hydrophobic spheres. The free energy of a configuration of two hydrophobic hard spheres is calculated as a function of their separation to understand the thermodynamic force between them mediated by water. The range of the hydrophobic interaction is found to be of the order of the equilibrium correlation length of water; beyond this range the hydrophobicity induced force is negligible. We also examine the free energy landscape corresponding to the two interacting hydrophobic spheres, and find a new intermediate state between the two states of separate and non-interacting spheres and a weakly bound cluster. The nature of this intermediate state changes depending on the size of the spherical particles, and even disappears beyond a minimum critical radius. Our results are relevant to the understanding of hydrophobic mediated interactions in coarse grained models of protein folding and protein protein interactions which, to date, have only accounted for hydrophobicity in an empirical way.

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29

Wong, Hau To. „Solvent nanofiltration for organometallic catalysed reactions“. Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429120.

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30

Hanif, Mohammed. „Mass transfer studies in solvent extraction“. Thesis, Teesside University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328022.

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31

Chimpalee, Dolrudee. „Applications of ion-pair solvent extraction“. Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336039.

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32

Ladikos, D. „Dissociation of haemoproteins on solvent precipitation“. Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374175.

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33

Shaw, Graham Andrew. „Solvent mediated synthesis of metal chalcogenides“. Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326065.

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34

Lukhezo, Muchinyarawo. „Reactive solvent extraction of amino acids“. Thesis, London South Bank University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245090.

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35

Wescott, Charles R. (Charles Reese). „The solvent dependence of enzymatic selectivity“. Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40595.

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36

Anthony, Renil J. „Solvent Extraction of Lipids from Microalgae“. Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1280854965.

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37

Blankenship, Elise. „Conserved solvent networks in GPCR activation“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1458221506.

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38

Stawikowska, Joanna. „Characterisation of organic solvent nanofiltration membranes“. Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/14732.

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Interests in application of organic solvent nanofiltration (OSN) technology based on synthetic membranes to molecular separation processes have been growing rapidly in recent years. The main classes of OSN flat sheet polymeric membranes are integrally skinned asymmetric (ISA) and thin film composite (TFC) membranes. A general goal of OSN membrane research is to improve membrane performance for specific non-aqueous applications, or to develop new separation processes. Most of the time the research is performed via trial–and–error methods, leading to extension of development time and increase of costs. This is partially because the structure of OSN membranes, particularly the size of their permeation pathway is largely unknown. The filtration characteristics are mainly determined by the membrane structure, which is dependent on various fabrication methods as well as polymer chemistry. However, a direct correlation between these factors has not been understood in detail, because the current characterisation techniques have limitations in studying polymer structures with dimensions at the macromolecular level. The pore size in nanofiltration (NF) membranes is believed to be less than 2 nm, which is a lengthscale at the edge of most available material characterisation techniques. For this reason, advanced methods to study the membrane morphology need to be explored or developed with the aim of elucidating the NF membrane structure, transport mechanisms, and to understand the relationship between the membrane structure and the separation characteristics. These objectives guided the work to development of a nanoscale characterisation method based on imaging the porous regions via probing the NF pores with nanoparticles (NP). Given that the probes provide high electron contrast, it is possible to map the pores formed between the polymer entanglements in the transmission electron microscope (TEM). This technique measures the pore size in situ, thus, a membrane is characterised during its operational state. The pore size was found to correlate well with the solute rejection and flux measured for a range of ISA and TFC membranes. The pore size distributions were then used together with a pore–flow model to simulate rejection curves. A further insight into the membrane structure, particularly the surface structure, was provided by atomic force microscopy (AFM), particularly phase imaging. This method was applied to characterisation of polymer packing at the membrane surface, leading to analysis of the correlations between the phase shift, filtration parameters and membrane preparation methods.

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39

See, Toh Yoong Hsiang. „Molecular separations with organic solvent nanofiltration“. Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/11320.

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This thesis firstly describes the application of organic solvent nanofiltration (OSN) in the recycle of asymmetric hydrogenation catalysts through the retention of the (often) larger catalyst whilst allowing the smaller products to penneate. This improves the catalyst tum over number (TON) and the further addition of the ionic liquid (IL) CyPhoslOl markedly improves the enantiomeric excess in the asymmetric hydrogenation of dimethyl itaconate using Ru-BINAP. The high molecular weight of the catalyst and IL allows them to be simultaneously recycled using an OSN membrane. Although this work identifies significant potential to further the application of OSN in homogeneous catalyst recycle, there is a lack of commercially available OSN membranes with good chemical stability across a range of organic solvents and with the ability to separate compounds in the NF range of 200-1000 g morl. The central part of this thesis addresses these issues through the development of various integrally skinned asymmetric polyimide OSN membranes. A consistent method to describe the penneation property of the molecular weight cut off (MWCO) has been developed. This allows the detennination of membrane performance and integrity across a range of different membranes and solvents. The variation of membrane separation perfonnance across the NF range has been achieved through cfanging various membrane fonnation parameters. Crosslinking of these membranes significa~tly enhances the chemical stability allowing stable perfonnances in a range of organic solvents including polar aprotic solvents. Coupling chemical crosslinking with the fonner methodology simultaneously improves the membrane chemical stability and allows membranes to be tailored for specific separations. Finally, this work also examines some initial steps leading to the scale up of OSN membranes to pilot scale through the use of spiral bound elements.

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40

Mack, Chris Alan. „Modeling solvent effects in optical lithography /“. Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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41

Low, Jian-Shen. „A study of organic solvent nanofiltration“. Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/35066.

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This thesis is concerned with the principal features of solvent resistant nanofiltration (SRNF), and in particular its potential in fuel processing. In the recent and more established literature, dense polydimethylsiloxane (PDMS) has been identified as a potential SRNF membrane with separation properties at a molecular level. This thesis investigates the transport and separation mechanisms of dense PDMS membranes in SRNF applications relating to the filtration of organic solvents (mixtures are mixed to simulate fuel). Simulated fuels were created which comprised representative organic solvents with organometallic (OM) and poly-nuclear aromatic (PNA) solutes. The solvent flux and solute rejection behaviour of the solvent-solute systems were studied using a cross-flow air-driven filtration apparatus and a range of operating regimes.

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42

Mandumpal, Jestin Baby. „The molecular mechanism of solvent cryoprotection“. Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/496.

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The cryopreservation of animal and human cells, tissues and organs as well as germplasm of endangered plant species is a key area in contemporary biotechnology. In this thesis, certain classes of chemicals known as cryoprotective agents (CPA) are investigated in detail. The structural, dynamic and vitrification properties of representative CPAs are studied using the state-of-the art molecular dynamics simulation techniques. The simulations provide a rationale at the molecular level of the cryoprotective properties of aqueous solutions of compounds such as DMSO, methanol and ethanol.This is a brief synopsis of the thesis:CHAPTER 1. This chapter provides a general introduction of various aspects of cryoprotection. A brief overview of the challenges that are encountered in the cryopreservation protocol is given, followed by a list of known cryoprotectants. Next various mechanisms to account for cryopreservation have been explained in detail. This section is followed by one of the important theme of this thesis, vitrification, and finally water and its properties.CHAPTER 2. This chapter discusses the theoretical background of molecular dynamics simulations and various analyses, and a brief overview of water forcefields.CHAPTER 3. Molecular dynamics simulations of DMSO in water elucidating its structural, dynamic and hydrogen bonding properties are described in this chapter. Comparison with its chemical analogue, Acetone, is made in an attempt to rationalise DMSO‟s exceptional properties in a wide range of temperatures.CHAPTER 4. Structural and hydrogen bonding properties of aqueous ethanol and methanol solutions have been described in this chapter.CHAPTER 5. Estimation of glass transition temperatures of aqueous mixtures of DMSO, acetone, ethanol, methanol and water using simulated annealing molecular dynamics techniques has been described in this chapter.CHAPTER 6. Important conclusions arising from this study and scope of the work have been summarised in this chapter.

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43

Zhou, Teng [Verfasser], und Kai [Akademischer Betreuer] Sundmacher. „Systematic methods for reaction solvent design and integrated solvent and process design / Teng Zhou ; Betreuer: Kai Sundmacher“. Magdeburg : Universitätsbibliothek, 2016. http://d-nb.info/112452245X/34.

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44

Van, Rensburg Eulouka Janse. „Solvent extraction of South African coal using a low volatile, coal-derived solvent / Eulouka Janse van Rensburg“. Thesis, North-West University, 2007. http://hdl.handle.net/10394/1855.

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Coal is an important fuel for countries with large coal reserves such as South Africa since it is expected that oil and natural gas prices will continue to rise. The Waterberg coalfield contains 40% of South Africa's remaining coal reserves, but due to the lack of a good infrastructure (water and railway) there are currently only a few operations in the Waterberg. The utilization of remote coal reserves, such as the Waterberg coalfield, is difficult and requires an investigation of possible coal conversion processes. The extraction of high-ash bituminous coal, using an organic solvent, had been studied by coal researchers before as a possible method to convert coal into valuable products. The purpose of the solvent is to extract organic material from the coal while the inorganic mineral matter (ash) is left behind. Advantages of the solvent extraction process include mild operating conditions compared to an indirect liquefaction process, low C02 release and coal as major utility since the solvent can be recycled. Therefore, the aim of this study was to investigate the solvent extraction of South African coal using a coal-derived solvent. Batch extraction experiments were carried out for two South African coals - one a vitrinite-rich coal (Waterberg) and the other an inertinite-rich coal (Brandspruit). A vitrinite-rich American coal (lllinois#6) was used as benchmark. Residue oil was the selected coal-derived industrial solvent used for the extractions. High extraction yields (d.a.f) were obtained for Waterberg (29-63%) and lllinois#6 coal (55-74%), while only limited success was achieved with Brandspruit coal (maximum 17%). This shows that solvent extraction, using residue oil as solvent, is a possible coal conversion process to convert vitrinite-rich South African coal into valuable products. For the operating conditions investigated in this study it was found that 370^ is the optimum extraction temperature and 5:1 the optimum solvent to coal ratio, while the particle size did not have a significant influence on the extraction yield. Continuous extraction experiments were carried out for the same two South African coals used in the batch extraction experiments and also with residue oil as solvent. Extraction temperatures and residence times were limited by the experimental setup. Negative extraction yields were obtained that could be explained by the effect of coal particles adsorbing compounds in the residue oil during the filtration step, which was performed at room temperature. To compensate for the adsorption process, the extraction yields were calculated with the extraction data at the lowest temperature as basis instead of the feed coal data. Extraction yields (d.a.f) of 20-52% were then obtained for the Waterberg coal and 3-12% for Brandspruit coal, with the highest extraction yield observed at 340°C and residence time of 12 min. In general, an increase in extraction yield with increase in temperature as well as with increase in residence time was observed. The shrinking-core model was used to describe the solvent extraction process and provided a good fit for the experimental data. Activation energies of 324 kJ/mol for Waterberg coal and 134 kJ/mol for Brandspruit coal were determined. Finally, it was found that most of the results of the continuous extraction experiments were in line with the results of the batch extraction experiments. In conclusion, the objectives of this investigation were met and form a good basis for further extraction research. In general it can be recommended to expand the conditions of this investigation to check the accuracy of the conclusions made. The most important areas for future research in developing a commercial-scale process include separation of residue coal from the extract, recycling of the solvent, and hydrogenation studies on the liquid extract product.
Thesis (M. Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2008.

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45

Wang, Ying. „Solvent uptake and swelling by a PS-DVB column packing and metal ion speciation by microdrop solvent extraction“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0009/NQ59693.pdf.

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46

Dreimann, Jens M. [Verfasser]. „Process Intensification in Homogeneous Catalysis - Catalyst Recovery via Thermomorphic Solvent Systems and Organic Solvent Nanofiltration / Jens M. Dreimann“. München : Verlag Dr. Hut, 2017. http://d-nb.info/1139538349/34.

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47

Dreimann, Jens [Verfasser]. „Process Intensification in Homogeneous Catalysis - Catalyst Recovery via Thermomorphic Solvent Systems and Organic Solvent Nanofiltration / Jens M. Dreimann“. München : Verlag Dr. Hut, 2017. http://d-nb.info/1139538349/34.

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48

Koren, David W. „Column hydrodynamics of solvent in pulp processing“. Thesis, University of Ottawa (Canada), 1987. http://hdl.handle.net/10393/5463.

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49

Lui, Amy M. Y. „Solvent exchange drying of gas separation membranes“. Thesis, University of Ottawa (Canada), 1988. http://hdl.handle.net/10393/5477.

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50

Duhayon, Christophe. „Copper solvent extraction by ultrasound-assisted emulsification“. Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210155.

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The goal of this research is to improve an extractive metallurgy process based

on solvent extraction. This process should fit the exploitation of small local

copper-rich deposits. In these conditions, the plant has to be as compact as

possible in order to be easily transported from one location to a subsequent

one. Improved extraction kinetics could ensure a high throughput of the

plant despite its compactness. In addition, the extraction reagent should

not be damaging for the environnement. On this basis, we propose to use

ultrasound-assisted solvent extraction. The main idea is to increase the

extraction kinetics by forming an emulsion in place of a dispersion thanks to

the intense cavitation produced by ultrasound. The benefit of this method

is to improve the copper extraction kinetics by increasing the interfacial

surface area and decreasing the width of the diffusion layer. We studied the

implementation of an highly branched decanoic acid (known as Versatic-

10®acid) as a copper extraction reagent dispersed in kerosene.

Emulsification is monitored through the Sauter diameter of the organic

phase droplets in aqueous phase. This diameter is measured during pulsed

and continuous ultrasound irradiation via a static light scattering technique.

The phenomenon of emulsification of our system by ultrasound is effective,

and the emulsification process carried out in the pulsed ultrasound mode is

at least as efficient as the emulsification obtained under continuous mode.

No improvement of emulsification is observed beyond a threshold time of

the ultrasound impulse. This may be attributed to a competition between

disruption and coalescence. The use of mechanical stirring combined with

pulsed ultrasound allows to control the droplet size distribution.

In presence of ultrasound, the extraction kinetics of Versatic-10 acid is

multiplied by a factor ten, and therefore reached a value similar to the kinetics

observed without ultrasound with an industrial extractant such as

LIX-860I®(Cognis). Extraction kinetics measurements are carried out by

monitoring the copper ion concentration in the aqueous phase with an electrochemical

cell.

We conclude that ultrasound-assisted emulsification can be implemented

under certain conditions. Emulsification is a first step, and the following

destabilization step has to be studied. The device using ultrasound-assisted

emulsification should be followed by an efficient settling-coalescing device. A

possible solution would be to promote emulsion destabilization by increasing

the ionic strength with an addition of MgSO4, a salt that is not extracted

by the extraction reagent in the considered range of pH.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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