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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Undersökningsmetodik för klorerade lösningsmedel i marken / Chlorinated solvents in soil and groundwater : Investigation methodology and analysis of completed investigations

Walger, Ellen January 2006 (has links)
<p>Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils. Chlorinated solvents can be harmful at low concentrations. Complete degradation can only occur under specific conditions. Because of the properties of these substances, investigation and analysis methodology are extra important for determining transport and risks in a contaminated area.</p><p>In this work, investigation and analysis methods for chlorinated solvents are described. Planning, fieldwork, modeling and risk analysis are described.</p><p>Projects concerning chlorinated solvents completed by Golder Associates AB have been compiled and analysed. Based on the compilation, conclusions have been drawn and statistics have been calculated. Investigations of the relation between concentrations in different media have been made as well as investigations of the relation between degradation products at different distances from the source and at different times after release. The data from the environmental investigations have been compared with theoretical literature values and modelling results.</p><p>The results show that there is a large natural variation in the data and that the differences between different areas are quite large. The results confirm the theory that the percentage of degradation products increases with distance from the source and with time from release. In addition, solvents with a higher degree of chlorination seams to appear to a greater extent in the soil and the more volatile substances seams to appear to a greater extent in the soil air.</p> / <p>Klorerade lösningsmedel är flyktiga klorerade organiska ämnen som kan vara skadliga för människor och miljön. Exempel på vanliga klorerade lösningsmedel är perkloreten, PCE och trikloreten, TCE. Klorerade lösningsmedel förekommer som markföroreningar främst efter användning som tvättvätska i kemtvättar och som avfettningsmedel i metallindustrin. Klorerade lösningsmedel är DNAPLs (dense non-aqueous phase liquids), det innebär att de är svårlösliga i vatten och att de sjunker och lägger sig på botten av akviferen. Fastläggningen i jorden är liten hos klorerade lösningsmedel som därmed är rörliga i marken. De är farliga redan vid små koncentrationer och fullständig nedbrytning sker endast under vissa förutsättningar. Ämnenas egenskaper gör att undersöknings- och analysmetodiken är viktig för att riktigt kunna bestämma deras utbredning och risk på ett förorenat område.</p><p>I detta arbete beskrivs undersöknings- och analysmetodiken för områden förorenade med klorerade lösningsmedel. Upplägg, fältarbete, modellering och riskbedömning beskrivs.</p><p>Projekt som handlar om klorerade lösningsmedel utförda av Golder Associates AB har sammanställts. Sammanställningen har analyserats och utifrån den har olika slutsatser dragits och statistik beräknats. Bland annat har samband mellan halter i olika medier samt samband mellan halter av nedbrytningsprodukter på olika avstånd från källan respektive efter olika lång tid från läckage har undersökts. Data från miljöundersökningarna har även jämförts med teoretiska litteraturvärden samt modelleringsresultat.</p><p>Resultatet visar att den naturliga spridningen av data är stor samt att resultaten skiljer sig åt mellan olika områden. Resultaten bekräftar teorierna att halten nedbrytningsprodukter ökar med avståndet från källan och med tiden samt att ämnen med högre kloreringsgrad finns i större utsträckning i jorden och att flyktigare ämnen finns i större utsträckning i porluften.</p>
272

Förorenade byggnader : Utvärdering av genomförda saneringar

Johannesson, Sofia January 2008 (has links)
<p>Nowadays there are several contaminated buildings that receive a new field of application. These buildings used to have industrial activities which contaminated the buildings with both organic and inorganic pollutants that can cause serious health problems. Now these buildings get new functions like office work, school buildings or daycare centers. But before these buildings can be used as for instance schools some kind of remediation has to be carried out to remove the contamination. The aim with this report was to make an inventory of available methods for remediation of contaminated buildings and to evaluate the result of some performed remediations. The buildings that were investigated in this report were contaminated with organic pollutants. This report includes a summary of the legislation that concerns contaminated buildings, health problems that solvents and oils can cause and information of available methods for remediation of polluted buildings. A survey was made and property holders of remediated contaminated buildings answered it. According to the survey it emerged that air-regulated floors and new floor constructions were the most commonly used methods for remediation. The choice of method was often a balance between time and economy. After the remediation it’s important to do inspections to make sure that the remediation had removed the contamination. Inspection can be made by measuring the indoor air. Another way to inspect a remediation is to send out surveys to those people who stay in the building. The most important aspect during the remediation is to guarantee peoples health. Results from the survey showed that air-regulated floors are a good remediation method and often used with good results. To make the remediation work easier generic guideline values for different building materials should be developed to be used in the analysis of the degree of the remediation.</p>
273

Ionic liquids as solvents in separation processes.

Warren, David Mercer. January 2003 (has links)
Due to the ever increasing need for sustainable development, the chemical and allied industries have been at the focus of much change. Decreasing tolerances on pollution via waste streams has resulted in a re-examination of many chemical processes. This has ushered in the era of 'green chemistry' which incorporates the synthesis of a process in both a sustainable and economically viable manner. In the petroleum and chemical industries, this has led to the search for alternatives to volatile organic compounds. Ionic liquids provide one such alternative. With a wide liquid phase and no measurable vapour pressure, ionic liquids have been found to be successful as a medium for reactions. Ionic liquids differ from high-temperature molten salts in that they have a significantly lower melting point. This work investigates the use of ionic liquids as solvents in separations. The work focuses on the separation of alpha-olefins from complex mixtures. The ionic liquids used in this study were: • l-methyl-3-octyl-imidazolium chloride • 4-methyl-N-butyl-pyridinium tetrafluoroborate • trihexyl-tetradecyl-phosphonium chloride Three experimental techniques used to evaluate ionic liquids were: • gas-liquid chromatography • liquid-liquid equilibria measurements • vapour-liquid equilibria measurements l-Methyl-3-octyl-imidazolium chloride ((MOIM)C1) was used as a stationary phase in gas-liquid chromatography. The solutes used were: • Alkanes: n-Pentane; n-Hexane; n-Heptane; n-Octane • Alkenes: 1-Hexene; 1-Heptene; l-Octene • Alkynes: l-Hexyne; l-Heptyne; 1-0ctyne • Cycloalkanes: Cyclopentane; Cyclohexane; Cycloheptane • Aromatics: Benzene; Toluene Activity coefficients at infinite dilution were measured at temperatures (298.15, 308.15 and 318.15) K. Values at 298.15 K ranged from 1.99 for benzene to 26.1 for n-octane. From the temperature dependence of the activity coefficients, the partial excess molar enthalpies at infinite dilution were calculated. These range from 2.0 kJ.mol'l for l-octyne to 7.3 kJ.mol·1 for n-pentane. (MOIM)C1 shows reasonable ability to separate 1-hexene from the longer n-alkanes and aromatics. 4-Methyl-N-butyl-pyridinium tetrafluoroborate (BuMePyBF) was used as a solvent in liquid-liquid equilibria measurements. The following systems were measured at 298.2 K: • LLE System 1: BuMePyBF4 + 1-Hexene + Toluene • LLE System 2: BuMePyBF4 + 1-Hexene + Ethanol • LLE System 3: BuMePyBF4 + 1-Hexene + 2-Butanone • LLE System 4: BuMePyBF4 + 1-0ctene + Ethanol LLE System 1 is a type 11 system and the other systems being type I. All systems exhibit a large two-phase region. LLE System 1 shows low distribution. LLE System 3 show almost equal distribution between phases resulting in a distribution ratio of close to 1. LLE Systems 2 and 4 show high distribution ratios at low concentrations of solute. LLE Systems 1 and 3 show low to moderate selectivity of the solvent towards the solute. LLE Systems 2 and 4 show high to moderate selectivity, but decrease exponentially with increasing solute concentration in the organic phase. For all systems investigated, the solvent shows no miscibility with feed solutions of low to medium solute concentration. The binodial curves were correlated to the Hlavaty equation, the beta function and the log gamma function. The correlations yielded acceptable results for LLE Systems 2, 3 and 4. The tie-lines were correlated to the NRTL model, with LLE systems 2 and 4 giving acceptable results and LLE systems 1 and 3 give excellent results. The following binary vapour-liquid equilibrium systems were measured: • Acetone + Methanol at 99,4 kPa • l-Hexene + 2-Butanone at 74.8 kPa The acetone + methanol system exhibits a minimum boiling azeotrope at 0.78 mole fraction acetone. The l-hexene + 2-butanone system exhibits a minimum boiling azeotrope at 0.83 mole fraction l-hexene. Trihexyl-tetradecyl-phosphonium chloride (CJ3C1PhCl was then added to the above systems in order to evaluate it as a solvent in extractive distillation. (CJ3C1PhCI shifts the azeotrope of the acetone + methanol system to a higher acetone concentration, but does not remove it altogether. (CJ3C1PhCI has a negative effect on the relative volatility of the l-hexene + 2-butanone, thus rendering it ineffective as an extractive distillation solvent for this system. Another aspect that was considered in this work was the production of an ionic liquid. Synthesis steps and experimental considerations were discussed. A major factor in the use of ionic liquids is the cost of the ionic liquid itself. The major problem associated with ionic liquids is the general lack of available information that is necessary for them to be implemented in a process. Ionic liquids show potential as solvents in liquid-liquid extraction for a number of systems. Their potential as solvents in extractive distillation is probably limited, due to their miscibility/immiscibility properties, to systems involving slightly polar to highly polar compounds. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.
274

Novel support materials for jetting based additive manufacturing processes

Fahad, Muhammad January 2011 (has links)
Inkjet printing (jetting) technology, due to its high speed of operation and accuracy, is utilised in Additive Manufacturing (AM) of three dimensional parts. Commercially available AM processes that use jetting technology include three dimensional printing (3DP by Z-Corporation), Polyjet (by Objet), Multi Jet Modelling (MJM by 3D Systems) and three dimensional printing by Solidscape. Apart from 3D Printing by Z-corporation, all the other jetting based processes require a support material to successfully build a part. The support material provides a base to facilitate the removal of the part from the build platform and it helps manufacturing of cavities, holes and overhanging features. These support materials present challenges in terms of their removability and reusability. This research is therefore, aimed towards finding a support material composition that can be used with jetting based AM processes. The support material should be easily removable either by melting or by dissolution and also, if possible, it should be reusable. AM processes often process materials with poor mechanical properties and therefore, the parts produced by these processes have limited functionality. In an attempt to obtain complex shaped, functional parts made of nylon (i.e. Polyamide 6), a new jetting based AM process is under research at Loughborough University. The process uses two different mixtures of caprolactam (i.e. the monomer used to produce polyamide). These mixtures are to be jetted using inkjet heads and subsequently polymerised into polyamide 6. Therefore, another aim of this research was to consider the support material s suitability for jetting of caprolactam. Two different polymers were researched which included Pluronic F-127 and methylcellulose (MC). Both these polymers are known for gel formation upon heating in aqueous solutions. Due to the inhibition of polymerisation of polyamide 6 by the presence of water, non-aqueous solvents such as ethylene glycol, propylene glycol and butylene glycol were studied. Since both F-127 and MC in the glycols mentioned above had not been studied before, all the compositions prepared and investigated in this report were novel. F-127 did not show gel formation in propylene and butylene glycol but formed a gel in ethylene glycol at a concentration of 25% (w/w) F-127. MC, on the other hand, showed gel formation upon cooling in all the three glycols at concentrations as low as 5% for ethylene glycol and 1% for both propylene and butylene glycol. These compositions were characterized using experimental techniques such as Fourier Transform Infrared (FTIR) spectroscopy, hot stage microscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A mechanism of gelation for both F-127 and MC in glycols is presented based on the results of these characterisation techniques. Viscosity and surface tension measurements along with the texture analysis of selected compositions were also performed to evaluate their suitability for jetting. All these compositions, due to their water solubility and/or low melting temperatures (i.e. near 500C) present the advantage of ease of removal. Removal by melting at low temperatures can also provide reusability of these support materials and thus advantages such as reduction in build cost and environmental effect can be achieved.
275

Detecting life on Mars and the life marker chip : antibody assays for detecting organic molecules in liquid extracts of Martian samples

Rix, Catherine S. January 2012 (has links)
The Life Marker Chip instrument, which has been selected to fly as part of the 2018 ExoMars rover mission payload, aims to detect up to 25 organic molecules in martian rocks and regolith, as markers of extant life, extinct life, meteoritic in-fall and spacecraft contamination. Martian samples will be extracted with a solvent and the resulting liquid extracts will be analysed using multiplexed microarray-format immunoassays. The LMC is under development by an international consortium led by the University of Leicester and the work described within this thesis was carried out at Cranfield University as part of the consortium’s broader program of work preparing the LMC instrument for flight in 2018. Within this thesis four specific areas of LMC instrument development are addressed: the investigation of immunoassay compatible liquid extraction solvents, the study of likely interactions of martian sample matrix with immunoassays, the development of antibodies for the detection of markers of extinct life and demonstration of solvent extraction and immunoassay detection in a flight representative format. Cont/d.
276

Using PCA to reveal hidden structures in the remediation steps of chlorinated solvents

Johansson, Glenn January 2017 (has links)
Chlorinated solvents such as trichloroethene (TCE) and perchloroethene (PCE) are commonly found in industrialized areas and can have major impact on human health and groundwater quality. The techniques for removing these substances from the subsurface environment is constantly being tuned and revised, and as such, the need for monitoring at such remediation sites is crucial. To find important correlations and hidden patterns between variables principle component analyses (PCA) and correlations matrixes were used on sets of field data from an existing remediation site in southern Sweden. Four important components were extracted in the following order; End products of dechlorination (EPD), second wave of dechlorination (SWD), first wave of dechlorination (FWD) and indicators of dechlorination (ID). The underlying pattern found in the data set was most likely derived from thermodynamic preference, explaining important correlations such as the correlation between iron and sulfate, the correlation between redox and degree of dechlorination. The law of thermodynamic preference means that we can (roughly) estimate the level of difficulty and/or the time it will take to remediate a polluted site.  These findings show that similar results shown in theory and laboratory environments also applies in the field and also that PCA is a potent tool for evaluating large data sets in this field of science. However, it is of great importance that the correlations are examined thoroughly, as correlation it not equal to causation.
277

Tools for Computer-Aided Molecular and Mixture Design

Austin, Nick Donnelly 01 May 2017 (has links)
This thesis explores mathematical optimization techniques to address the computeraided molecular and mixture design problems (CAMD/CAMxD). In particular, we leverage the power of mixed-integer linear programs (MILPs) to quickly and efficiently design over the massive chemical search space. These MILPs, when coupled with state-ofthe- art derivative-free optimization (DFO) methods, make for an efficient optimization strategy when designing mixtures of molecules or when considering a single molecule design problem that involves difficult thermodynamics or process models. In the first chapter, we provide a very general overview of the field of CAMD as addressed from the perspective of mathematical optimization. We discuss many relevant quantitative structure-property relationships (QSPRs) and provide constraints typically used in CAMD/CAMxD optimization problems. The second chapter introduces our DFO-based molecular/mixture design algorithm and describes how this approach enables a much greater molecular diversity to be considered in the search space as compared to traditional methods. Additionally, this chapter looks at a few case studies relevant to crystallization solvents and provides a detailed comparison of 27 different DFO algorithms for solving these problems. The third chapter introduces COSMO-RS/-SAC as alternatives to UNIFAC as the method used to capture mixture thermodynamics for a variety of CAMD/CAMxD problems. To fully incorporate COSMO-RS/-SAC into CAMD, we introduce group contribution (GC) methods for estimating a few necessary parameters for COSMO-based methods. We demonstrate the utility of COSMO-RS/-SAC in a few case studies for which UNIFAC-like methods are insufficient. In the fourth chapter, we investigate reaction solvent design using COSMO-based methods. COSMO-RS is particularly suitable for these problems as they allow for modeling of many relevant species in chemical reactions (transition states, charges, etc.) directly at the quantum level. This information can be immediately passed to the CAMD problem. We investigate a number of solvent design problems for a few difficult reactions. We summarize the work and provide a few future directions in the final chapter. Overall, this thesis serves to push the field of CAMD forward by introducing new methods to more efficiently explore the massive chemical search space and to enable a few new classes of problems which were previously untenable.
278

The electrodeposition of tin coatings from deep eutectic solvents and their subsequent whisker growth

Stuttle, Christopher January 2014 (has links)
Tin electrodeposits produced from aqueous electrolytes are frequently used within the electronics industry due to their high solderability and corrosion protection. One limitation to using these deposits is their spontaneous formation of long conductive filament whiskers. These whiskers grow post-electrodeposition and increase the risk of unwanted electrical shorts within electronic devices. In this thesis, tin electrodeposits produced from a proprietary bright acid Tinmac electrolyte, currently used in industry, were studied. Electrodeposits were produced using a range of current densities with and without agitation and were characterised with respect to crystallographic orientation, topography and surface finish. Moreover, the intermetallic compound (IMC) growth produced at the copper substrate-tin coating interface was assessed over a period of time as its growth is considered to be a significant driving force behind whisker formation. In addition, a technique for the electrochemical anodic oxidation of tin electrodeposits on copper substrates was developed. This technique was used throughout this project for the study of IMC growth from tin electrodeposits as it was able to effectively remove the tin whilst leaving the IMCs and substrate unaffected. Ionic liquids exhibit promising electrochemical characteristics for electrodeposition but are still not widely utilised in industry. Their ability to deposit tin coatings has been studied in the present investigation. Trials concentrated on process optimisation to produce uniform electrodeposits by varying current density, SnCl2.2H2O concentration, and electrolyte composition. These deposits were then characterised and compared to tin coatings of similar thickness produced from Tinmac with respect to topography, surface finish, crystallographic orientation, IMC growth, and whisker propensity. Electrodeposits produced from the ionic liquid electrolyte exhibited a different crystallographic texture, topography, and IMC growth compared to those produced from Tinmac. Moreover, the deposit produced from the ionic liquid featured increased whisker growth compared to those produced from Tinmac, but in a wider context, far less growth than conventional tin electrodeposits in the literature. In addition, by exploiting other electrochemical characteristics of ionic liquids, such as their large potential window, future work may be able to produce novel tin or tin alloy electrodeposits which may further reduce the whisker propensity of deposits produced in this investigation.
279

Analysis of Integrated Gasification Combined Cycle power plants and process integration with pre-combustion carbon capture

Kapetaki, Zoe January 2015 (has links)
Integrated Gasification Combined Cycle (IGCC) power plants have been considered as one of the best options for energy production in an environmental friendly manner. IGCC power plants are demonstrating better results, both in terms of plant performance and economics, when compared to a Pulverised Coal (PC) power plant with CO2 capture. The additional components required for an IGCC power plant when it is desired to operate in CO2 capture mode, give research potential with respect to an improved IGCC power plant performance. The IGCC power plant design framework studied and developed was based in DOE/NETL report and is presented. The conventional and CO2 capture IGCC power plants have been benchmarked in rigorous process flow diagrams developed using the commercial software Honeywell UniSim Design R400. As an essential part of the Innovative Gas Separations for Carbon Capture project (IGSCC EPSRC – EP/G062129/1) predictive simulation tools were produced to investigate the IGCC performance. The case studies considered include different gasification options for non-capture and carbon capture IGCCs, with a two stage Selexol process for the CO2 capture cases. Particular effort has been made to produce an accurate simulation component to describe the behaviour of the syngas in the Selexol solvent. The two stage Selexol configuration was investigated in detail and novel schemes are presented. No similar approaches have been reported in the literature, in terms of the proposed configuration and the capture efficiency. Moreover, innovative CO2 capture schemes incorporating combined units of physical absorption and membranes have been examined with respect to the power plant’s performance. In this thesis, contrary to other studies, all simulations cases have been conducted in unified flow diagrams. The results presented include overall investigations and can be a helpful tool for engineers and stakeholders in the decision making process.
280

Estudo da atividade e estabilidade de lacases em líquidos iônicos / Study of activity and stability of laccases in ionic liquids.

Batistela, Daniela Moraes 13 April 2011 (has links)
Neste trabalho foram estudadas a atividade e a estabilidade de lacases dos fungos Coriolus hirsutus e Trametes versicolor em meio aquoso contendo líquidos iônicos (LI) como co-solventes, com o objetivo de se obter informações sobre os efeitos desses solventes na atividade enzimática. Foi avaliado o efeito de onze LI (cátions: tetrabutilamônio, 1-butil-3-metilpiperidina e 1-alquil-3-metilimidazólios; combinados com ânions: brometo, cloreto, metilsulfato, metanossulfonato e tetrafluorborato) em diferentes frações molares em meio aquoso tamponado com ácido acético (0,1 mol L-1, pH 4,7 e 25 &#176;C). De um modo geral, a atividade inicial das lacases nos diferentes líquidos iônicos foi inferior à obtida em solução aquosa somente tamponada. O aumento da concentração dos LI também resultou no decréscimo da atividade enzimática. Tanto os resultados obtidos para atividade, como para estabilidade enzimática, se correlacionaram bem com a série de Hofmeister, que ordena os íons de acordo com suas propriedades cosmotrópicas/caotrópicas. Ânions cosmotrópicos e cátions caotrópicos estabilizam proteínas, enquanto ânions caotrópicos e cátions cosmotrópicos as desestabilizam. As lacases estudadas foram fortemente inibidas na presença dos ânions caotrópicos Br- e BF4-. Entre os LI utilizados neste trabalho, o metanossulfonato de 1-etil-3-metilimidazólio foi co-solvente mais promissor para lacase. Os dados cinéticos das reações enzimáticas em metanossulfonato de 1-etil-3-metilimidazólio e metanossulfonato de 1-butil-3-metilimidazólio, utilizando os substratos catecol e siringaldazina, revelaram que o decréscimo da atividade enzimática é resultado do aumento da constante michaeliana. Os resultados obtidos da estabilidade e temperatura de transição de desnaturação térmica da lacase em LI formado por MeSO3-, cosmotrópico, foram comparáveis aos obtidos em tampão. A ordem crescente de atividade e estabilidade da lacase em líquidos iônicos para cátions foi BuN+&#8776;BMPP+&#8776;BMIM+&#60;EMIM+, enquanto para ânions foi Br-&#8776;BF4- < MeSO4- < MeSO3-. A diminuição da eficiência catalítica da reação (Kcat/Km) em meio contendo líquido iônico foi proporcionada principalmente pelo aumento da Km. Líquidos iônicos têm se apresentado como potenciais solventes para utilização em biocatálise. As propriedades físico-químicas dos LI podem ser moduladas pela combinação de diferentes cátions e ânions, visando características diferenciais para atividade enzimática. O estudo do mecanismo catalítico e dos efeitos específicos dos íons é de fundamental importância para a utilização vantajosa desses solventes em reações enzimáticas. / In this study, the activity and stability of laccase of T. versioclor and C. hirsutus were studied in ionic liquid (IL)-containing aqueous systems to provide valuable information with regard to the effect of IL on the enzyme activity. The effect of IL on the laccase performance was investigated by comparing the activity, stability, kinetic (such as Km, Vmax) and thermal denaturation. An excessive amount of these ILs in the reaction systems resulted in decline in enzymatic activity. Both activity and stability of the enzyme correlate well with the Hofmeister series in terms of the salt\'s kosmotropic/chaotropic properties. Proteins are usually found to be stabilized by a kosmotropic anion and a chaotropic cation and destabilized by a chaotropic anion and a kosmotropic cation. Laccases strong had been inhibited presence of chaotropic anions Br- and BF4-. Among the IL used here, 1-etyl-3-methylimidazoliun methanesulfonate was the most promising IL for laccase. A detailed analysis of kinetic data in the presence of catecol and syrigadalzine as substrate revealed that the decrease in the laccase activity was a result of increase in Km. Equal stability the transition temperature for the thermal denaturation of laccase of T. versioclor in ionic liquids based in MeSO3- (kosmotropic) was comparable to that of the control sample. It was observed an ion effect on the laccase activity and stability, for cations this parameters values increased in the order BMIM+&#8776;BuN+&#8776;BMPP+ < EMIM+; while for anions the order is Br-&#8776;BF4- < MeSO4- < MeSO3-. Also an increase in Km is correlated with the decrease in the catalytic reaction efficiency (Kcat/Km) in medium containing ionic liquid. Design and use of water-mimicking IL composed of chaotropic cations and kosmotropic anions may facilitate the applications of IL in biotransformations.

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