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ENZYME CATALYZED SYNTHESIS IN IONIC LIQUIDSFurlong, Danelle Lynn 13 September 2007 (has links)
No description available.
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Bioinspired Ion Pairs Transforming Poorly Water-soluble Compounds into Protic Ionic Liquids and Deep Eutectic Solvents / Bioinspirierte Ionenpaare Wandeln Schlecht-wasserlösliche Verbindungen in Protische Ionische Flüssigkeiten und Tiefe Eutektische LösungsmittelGüntzel, Paul Mathias January 2022 (has links) (PDF)
Microbial, mammalian and plant cells produce and contain secondary metabolites, which typically are soluble in water to prevent cell damage by crystallization. The formation of ion pairs, e.g. with carboxylic acids or mineral acids, is a natural blueprint to keep basic metabolites in solution. It was aimed at showing whether the mostly large carboxylates form soluble protic ionic liquids (PILs) with basic natural products resulting in enhanced aqueous solubility. Furthermore, their supramolecular pattern in aqueous solution was studied. Thereby, naturally occurring carboxylic acids were identified being appropriate counterions for natural basic compounds and facilitate the formation of PILs with their beneficial characteristics, like improved dissolution rate and enhanced apparent solubility. / Mikrobielle, Säugetier- und Pflanzenzellen produzieren und enthalten Sekundärmetaboliten, welche in Wasser gelöst vorliegen, um Zellschäden (z.B. durch Kristallisation) zu vermeiden. Die Bildung von Ionenpaaren, beispielsweise mit Carbonsäuren oder Mineralsäuren, ist eine natürliche Strategie, um basische Metaboliten in Lösung zu halten. Es sollte gezeigt werden, dass die vergleichsweise großen Carboxylate lösliche protische ionische Flüssigkeiten (PILs) mit basischen Naturstoffen bilden, was zu einer verbesserten Wasserlöslichkeit führt. Weiterhin wurde das supramolekulare Verhalten der PILs in wässriger Lösung untersucht. Dabei wurden natürlich vorkommende Carbonsäuren als geeignete Gegenionen für natürliche basische Verbindungen identifiziert. Die resultierenden PILs zeigten eine verbesserte Auflösungsrate und verbesserte scheinbare Löslichkeit.
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Synthesis and Characterization of Polymeric Ionic Liquids and Applications in Solid-Phase Microextraction Coupled with Gas ChromatographyMeng, Yunjing 19 September 2011 (has links)
No description available.
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1-Alkyl-3-Methylimidazolium bis(pentafluoroethylsulfonyl)imide Based Ionic Liquids: A Study of their Physical and Electrochemical PropertiesDeCerbo, Jennifer N. 13 August 2008 (has links)
No description available.
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A Comparison Of Physical And Electrochemical Properties Of Two Ionic Liquids Containing Different Cations: 1-Butyl-1-Methyl-Pyrrolidinium Beti And 1-Butyl-3-Methyl-Imidazolium BetiKennedy, Edward Nelson 30 September 2009 (has links)
No description available.
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COMPARISON OF THE ELECTROCHEMICAL PROPERTIES OF ETHANOL IN PERCHLORIC ACID AND IONIC LIQUIDSFelix-Balderrama, Sandra 09 December 2009 (has links)
No description available.
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Thermal and Electrochemical Characterization of Cathode Materials for High Temperature Lithium-Ion Batteries in Ionic LiquidsShoaf, Jodie R. 07 April 2010 (has links)
No description available.
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1-Alkyl-3-Methylimidazolium bis(trifluoromethylsulfonyl)imide Based Ionic Liquids: A Study of Their Physical and Electrochemical PropertiesDutton, Charles William 13 July 2010 (has links)
No description available.
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Process Development and Techno-Economic Analysis for the Recovery of Rare Earth Elements and Critical Materials from Acid Mine DrainageMetivier-Larochelle, Tommee 17 January 2023 (has links)
Rare earth elements (REE) exhibit particular and unique properties that render them essential to technological applications. Of particular interest is their involvement in the transition toward global sustainability and their military applications. The magnetic properties of the rare earth elements is of primordial importance to sustainable development. More specifically, terbium and dysprosium are two elements with no known substitutes in critical applications and with no domestic or allied sourcing available. These elements are currently mined by in-situ leaching of ion-absorbed clays, mostly from illegal operations in Myanmar financed by Chinese companies. The demand from both elements, and for the other magnet rare earths is projected to growth at very high rates through 2035 while the world undergoes a transition toward sustainability, and a drastic reduction in greenhouse gases emissions. Our team has been evaluating the potential of acid mine drainage (AMD) as a source of rare earth elements and critical materials (CM). Acid mine drainage is the result of in-situ generation of sulfuric acid due to the weathering of sulfide ores. It is a significant legacy environmental issue and one of the largest pollutants in many mining districts throughout the world. The objective of the present work is to provides a roadmap for the utilization of AMD as a critical material feedstock to preserve the independence of the United States of America with regards to these materials. To that effect, a fundamental economic assessment of REE/CM recovery from AMD using a network sourcing strategy in addition to a robust, flexible feedstock separations and refining facility was undertaken. A techno-economic analysis of the extraction, refining, separation and reduction to metal is presented along with a sensitivity analysis.The results of this analysis show that, with the exception of the minimum price scenario, all operational configurations have positive economic indicators with rates of return varying from 25% to 32% for the contemporary price scenario. This is primarily due to the very high enrichment in terbium and dysprosium of AMD. The optimal configuration was determined to be production of Co, Mn, and all REEs except for mischmetal, which is not recovered. Sensitivity analysis and Monte Carlo Simulation show that capital cost and HCl consumption are the two major factors influencing rate of return, thus indicating opportunities for future technology development and cost optimization. In order to reduce both the capital and operation cost of the facility, alternative ionic liquids extractants based on conventional acidic extractants where synthesized and investigated. The results show that the ionic liquids varied in performance, with [c101][D2EHP] and [c101][EHEHP] performing poorer than their conventional counterparts and [c101][c572] performing better. The performance of [c101][c572] was 13% superior to Cyanex 572, 20% superior to EHEHPA and 27% superior to D2EHPA the current commercially used extractants. Recommendations for further study on [c101][c572] include stripping tests, continuous pilot testing, and techno-economic analysis. The test work revealed that zinc and to a lesser extent calcium were significant deleterious elements in the solvent extraction circuit, and that selective removal would significantly reduce the acid-base consumption of the separation circuit. A process was developed to selectively remove calcium and zinc from AMD-derived feedstock and from REE products. The ammonium chloride leach process offer many advantages, including the possibility of closing the cycle by using carbon dioxide sequestration as a step to regenerate the ammonium chloride in a zero-discharge process. / Doctor of Philosophy / A younger me: - What are these elements in the bottom of the periodic table?
My high school chemistry teacher: - "Don't waste time there, these are of no concern." Twenty years later, technological developments and the imperative to transition away from fossil energy to mitigate climate change have brought the rare earth elements, a series of 17 elements with unique properties to the forefront of the conversation. In addition to an organic increase in demand, the recent supply chain consolidation by China is adding a geopolitical risk to the equation. The magnetic properties of the rare earth elements is of primordial importance to sustainable development and to our military technology. More specifically, terbium and dysprosium are two elements with no known substitutes in critical applications and with no domestic or allied sourcing available. These elements are currently mined from illegal operations in Myanmar, with the support of Chinese companies. The demand from both elements, and for the other magnet rare earths is projected to growth at very high rates through 2035 while the world undergoes a transition toward sustainability, and a drastic reduction in greenhouse gases emissions. Given the important of the rare earth elements, and the absence of significant deposits in the united states, with the exception of the Bear Lodge and Elk Creek deposits, the Department of Energy has mandated academic institution of evaluating alternative sources of rare earth elements. Our team has been evaluating the potential of acid mine drainage as a source of rare earth elements and critical materials. Our team has surveyed many acid mine drainage sources and determined that many sites are highly enriched in terbium and dysprosium. Acid mine drainage is a legacy environmental issue related to past problematic mine development techniques. In the problematic mines. these acidic mine waters are permanently generated and if not treated can have severe impacts on water streams in which they flow. The toxicity of the acid mine drainage on the environment is due to its high acidity and significant levels of toxic metals. Acid mine drainage can be recognized by their yellow to red tint. It is treated by reacting it with a neutralization agent, which results in treated water and a sludge. The sludge is dewatered and stored in tailing impoundments. I have designed a process for the economical recovery of rare earth elements and critical materials from acid mine drainage. The cost to build and operate the facility was derived and it was determined that the project could be further enhanced by reducing the plant chemical reagent consumption. One specific category of chemical referred to as extractant, is central to the rare earth separation process. A novel variation on the standard extractants has been evaluated and promises to provide significant savings. While the extractants were investigated, it was noticed that some impurities such as zinc and calcium created issues in the circuit. I then developed a process for their selective removal. The process also provide a net carbon dioxide sequestration potential.
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Nano-Confined Room-Temperature Ionic Liquids for Electrochemical ApplicationsHe, Yadong 28 February 2018 (has links)
Room-temperature ionic liquids (RTILs) and their derivatives are promising electrolytes for electrochemical devices including supercapacitors. Understanding the behavior of RTILs in these devices is critical for improving their performance.
The energy density of supercapacitors can be improved greatly by using RTILs as electrolytes and nanoporous carbon as electrodes, but the mechanism of the charge storage using these materials is not well understood. In this dissertation, the diffusion and charging dynamics of RTILs in nanopores are studied. The results show that ion packing typically plays the most important role in ion diffusion. The study also demonstrates that the cyclic charging and discharging of a pore can exhibit a number of interesting features (e.g., sloshing of ionic charge along the pores during cyclic scans), which help explain experimental observations such as the negligible contribution of co-ions to charge storage at high scan rates.
Solid electrolytes with both high ionic conductivities and excellent mechanical strength are needed in many electrochemical devices. The invention of ion gels featuring aligned polyanions immersed inside RTILs has shown promise in meeting this demand, but the mechanism behind their superior mechanical strength remains elusive. Using molecular simulations, it is discovered that the high elastic moduli of model PBDT ion gels originate from the RTIL-mediated interactions between the polyanions. This insight is useful for future design of ion gels to improve their transport and mechanical properties. / Ph. D.
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