Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Non-polar Solvents"”.
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Solvent-induced modifications of the morphology and solid-state properties of ibuprofen
… techniques indicated that crystals grown from non--polar solvents were more strained. In conjunction with solution NMR results (which showed differences in molecular association in solvents of varying polarity) this led to two different growth mechanisms being proposed. The crystal structure of …
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Hypercoiling and hydrophobically associating polymers : interfacial synthesis, surface properties and pharmaceutical applications
… PLETESA was found to be soluble in both polar and non-polar solvents and the hydrophobic/hydrophilic balance could be modified by partial saponification (66-75%) of the ethyl ester side chains. Surface or interfacial tension/pH profiles were used to assess the conformation of both the …
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Selective hydrogenation of α,β[alpha,beta]-unsaturated aldehydes towards clean synthesis over noble metal catalysts in mass transfer efficient three phase reactors
… Aldehyde acetals were produced in polar solvents, but not in non-polar solvents. Two methods can be used to obtain hydrocinnamaldehyde selectivity without reduction of the carbonyl double bond: (1) by using non-polar solvents such as toluene; (2) by incorporating poisons or …
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The Triplex Diels-Alder Reaction: An Investigation of Enantioselectivity and Scope
… sensitizers, (-)1,1$\sp\prime$bis(2,4-dicyanonaphthalene) and (-)1,1$\sp\prime$bis(2,10-dicyanoanthracene). Irradiation of an optically active sensitizer in non-polar solvents containing substituted trans-$\beta$-methylstyrenes and cyclic dienes yielded endo (4+2) adducts with …
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Role of adsorption in catalysis: applications of NMR relaxometry
… aldehyde and the effect of different solvents on the activity and product distribution was studied at 298 and 373 K. A series of polar protic, polar aprotic and non polar solvents was investigated. Results showed higher initial reaction rates in non polar solvents but higher …
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Direct measurement and analysis of cyclohexadienyl oxidation
… relative concentration over time measured in non-polar solvents in both the presence and absence of oxygen. Several analytical and numerical models of the chemistry were constructed to explain a puzzling discrepancy in the reported liquid and gas phase reaction rates.
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ΕΝΔΟΜΟΡΙΑΚΗ ΦΩΤΟΚΥΚΛΟΠΟΙΗΣΗ ΤΗΣ ΚΑΡΒΟΝΗΣ ΠΡΟΣ ΚΑΡΒΟΝΟΚΑΜΦΟΡΑ
… (2) (TYPE) HAVE BEEN DETERMINED IN NON POLAR AND POLAR SOLVENTS, UNDER NITROGEN AND IN AIR-EQUILIBRATED SOLUTIONS. QUENCHING BY OXYGEN HAS BEEN OBSERVED ONLY IN NON POLAR SOLVENTS, BENZENE 01 --> 2=0.0025 UNDER NITROGEN AND 0.0012 IN AIR-EQUILIBRATED SOLUTIONS. SENSITIZATION …
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The Design and Synthesis of Novel Chiral Z-Nitrones with Applications Towards the Syntheses of Enantiomerically Pure 4-Hydroxy Amino Acids
… amino acids have been synthesized via 1,3-dipolar cycloadditions of novel Z-nitrones and substituted olefins. Three achiral nitrones were synthesized in pursuit of a conformationally stable yet reactive Z-nitrone. The carboisopropoxynitrone was determined to be the best synthon in …
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Structural studies of coordination networks based on multitopic organic ligands and silver(I) salts
… structures. When crystallized from non-polar solvents, the characteristic network motif in the complexes of silver(I) triflate with ditopic, linear ligands is always 2-connected infinite chains. In contrast, trigonal, tritopic ligand complexes form 3-connected structures. A …
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Funktionalisierte hierarchisch gebildete Helicate
… The first recognition step generates a mononuclear complex of three ligands and one metal ion. In a second recognition process two mononuclear complexes connect by three lithium ions to a helicate. Due to statistics a racemic mixture of P- and M- helicate is formed. The helicate has a …
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Supramolekulinių vamzdelinių struktūrų sintezė biciklo[3.3.1]nonano pagrindu /
… stereochemical multiplicity of the bicyclo[3.3.1]nonane framework for the construction of chiral, C2-symmetric supramolecular preprogrammed synthons containing hydrogen bonding recognition patterns at both ends of the molecule. The resulting cleft molecules would be utilized for the formation of …
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Nonaqueous Synthesis of Metal Oxide Nanoparticles and Their Surface Coating
… metal oxide nanoparticles via high temperature nonaqueous solution processes and the formation of core-shell structure metal oxide composites using some of these nanoparticles as the core with silica, titania or polymer as shell via a modified microemulsion approach. In the first part, the …
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Extractives from Sitka spruce
… can be extracted from wood or bark by means of polar or non-polar solvents. Extractives are derived mostly from the metabolic processes of the tree, particularly the sapwood to heartwood transformation. The first objective of the research was to study the distribution of extractives within Sitka …
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Supramolecular Chemistry at the Polymer-Oil Interface
… order to study the supramolecular interaction in non-polar solvent, a series of rotaxanes were synthesised with viologen-cucurbit[8]uril cores and bulky stopper groups to prevent unthreading of the cucurbituril as well as enhancing the solubility of the system. The two components were linked via …
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Radiofrequency heating of nanoclusters and nanoparticles for enzyme activation
… Applications include remote drug delivery and noninvasive cancer therapy. The underlying objective is to increase temperatures precisely where desired without heating the surroundings. Before our work, the replicable limit of this precision has been in the micrometer range. To investigate the …
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Applications of ROMP Polymers
… the binding properties of the SPPs by heating in polar or non-polar solvents (water/acetonitrile). The SPPs are also able to remember their stimuli-induced binding properties even when removed from the switching environment. In this project, our goal is to use these tunable polymer gels for the …
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Lithium and indium quinoneoximic complexes and their application in scintillation counting
… complexes of lithium derived from 1,2-naphthoquinone 1-oxime and 1,2-naphthoquinone 2-oxime have been prepared and characterised using analytical, spectroscopic and thermal gravimetric techniques. I.r. studies indicate that the ligands in these complexes are essentially quinoneoximic in …
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Advancement of the Hydrophobic-Hydrophilic Separation Process
… by displacement (DbD). The process uses non-polar solvents (usually short-chain alkanes) to selectively displace water from particle surfaces and to agglomerate fine coal particles. The resulting agglomerates are subsequently broken (or destabilized) mechanically in the next stage of the …
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Thermal and chemical analysis of carbonaceous materials: diesel soot and diesel fuel reactor deposits
… the SOF was performed using GC-MS analysis. Five solvents (hexane, cyclohexane, toluene, methanol and acetone) were compared with dichloromethane, the most extensively used solvent for the extraction of soot with respect to their ability to extract a variety of species, including polyaromatic …
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Flame-based synthesis of multi-component metal nanoparticles and conductive inks
… nanopowders are easily dispersed in organic non-polar solvents to form uniform nano-inks. The potential low-cost and scalable nature of the process for producing these nano-inks could make them promising for use in printed electronics and in pen-on-paper applications.
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