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Showing 1 to 20 of 37 for “"microemulsions"”.
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Microemulsions formation, stability and their characterisations
… applications, droplet combustion of w/o microemulsions is also studied for different surfaces (i.e. silica, oxidised Fecralloy and catalyst coated Fecralloy) in the temperature range of 313-573K. Formaldehyde and acetaldehyde are formed as intermediate combustion products. Thus the …
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Transport properties of micellar solutions and microemulsions.
Binary nonionic surfactant-water systems were studied prior to the more complex nonionic surfactant-water-oil systems. Phase diagrams were determined for the tetraoxyethylene dodecylether (C[12]E[4])-water and the Brij 30-water systems; the available hexaoxyethylene dodecylether (C[12]E[6])-water …
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Magnetic resonance investigations of pH in microemulsions
… micelles formed in CTAB, Triton-X and AOT microemulsions. These techniques have enabled visualisation of propagating acidity fronts in the bromate-sulfite reaction using magnetic resonance imaging. Contrast agents that are sensitive to pH were investigated in aqueous and microemulsion …
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Magnetic resonance studies of chemical reactions in microemulsions
The Belousov-Zhabotinsky (BZ) reaction is the preeminent oscillating chemical reaction for the study of pattern formation in reaction-diffusion systems. The dispersal of the reaction in a water-in-oil AOT microemulsion (BZ-AOT reaction) gives rise to an extended range of patterns, including dash …
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Linker-based Lecithin Microemulsions as Transdermal Drug Delivery Systems
The interest in microemulsions as transdermal delivery systems have been motivated by their large surface area for mass transfer, their high solubilization capacity of hydrophobic actives, and their ability to improve skin penetration. Lecithins (mixtures of phospholipids similar to those find in …
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Novel microemulsions with an anionic/non-ionic surfactant mixture
Mikroemulsionen bestehen im einfachsten Fall aus Wasser, Öl und Tensid(en). Es handelt sich dabei im Gegensatz zu normalen Emulsionen um transparente, thermodynamisch stabile Phasen. Diesen makroskopisch einphasig erscheinenden Systemen liegen jedoch hoch komplexe Nanostrukturen zu Grunde. Die in …
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Diffusion of proteins inside crowded structures generated using microemulsions
Microemulsions are thermodynamically stable mixtures of water, oil and surfactant. In the case of microemulsions based on sugar surfactants a cosurfactant as an additional component is necessary, most often a short-chain alcohol. In this thesis mainly pure surfactants are used. The focus is on …
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Microemulsions containing centella asiatica extract as antioxidant and anti-acetylcholinesterase agent
The treatment of Alzheimer's disease (AD) has gained much attention due to the current and predicted prevalence of the disease. Centella asiatica hydroalcoholic extract (CAHE), lemongrass essential oil (LGEO) and virgin coconut oil (VCO) presenting antioxidant and acetylcholinesterase inhibition …
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The structure and kinetics of oil-in-water microemulsions stabilised by nonionic surfactants
… the single phase (10) alkane oil-in- water (01W) microemulsions stabilised by nonionic surfactants of the general structure H-(CH2)n(OCH2CH2)m-OH, abbreviated to CnEm. The aims were to attempt to characterise their behaviour in terms of the effect of the different constituents n, m, and alkane oil …
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A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
… curvatures was developed and applied to various microemulsions. The method involves the use of a clipped random wave model with an inverse 8th order polynomial spectral function. The spectral density function contains three basic length scales : the inter-domain distance, the coherence length, …
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Aplicação de microemulsões na solubilização de frações pesadas de petróleo
This work presents studies related to the use of microemulsions in the solubilization of heavy crude oil fractions responsible by the formation of deposits. The first stage of the work was addressed to the construction of phases diagrams, with the intention of determining the area within which the …
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Investigation of the NOx and PM emissions from a diesel engine operating on nanoemulsified fuels
… compared to published results for conventional microemulsions. There is no decrease in indicated fuel conversion efficiency for the nanoemulsions. Fer a 9% water nanoemulsion specific NOx emissions are reduced by l 3 - 20% and specific PM emissions are reduced by 15 - 20% compared to the base …
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Microemulsion and macroemulsion behaviour of systems containing oil, water and nonionic surfactant
… made to correlate some equilibrium properties of microemulsions with the formation and stability of macroemulsions. Studies have been mainly limited to water-in-oil (W/O) systems stabilised by pure nonionic surfactants of the poly-oxyethylene alkyl ether (CnEm) type. Initially however, a brief …
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Green Photochemistry: The synthesis of fine chemicals with sunlight
… (polymer supported) synthesis, ionic liquids, microemulsions and supercritical fluids. Of these methods microemulsions proved most effective, with isolated yields of up to 88% (4 hours).
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Nanosized iron crystallites for Fischer-Tropsch synthesis
… were prepared via precipitation in water-in-oil microemulsions in which water-to-surfactant ratio was the main design parameter. The study was subdivided into firstly characterisation of a suitable water-in-oil microemulsion system. Secondly preparation of nanosized oxidic iron crystallites with …
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Amphiphilic BAB-triblock copolymers bearing fluorocarbon groups : synthesis and self-organization in aqueous media
… their ability to stabilize emulsions and microemulsions and the wetting behaviour of their aqueous solutions on different substrates was investigated. The behaviour of the fluorine end-functionalized polymers to form micelles was studied applying DLS measurements in diluted organic …
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Influence of hydrophobically modified polyelectrolytes on nanoparticle synthesis in self-organized systems and in water
… the oppositely charged polyelectrolytes and the microemulsions formed using these surfactants present a large water-in-oil region. Subsequently, the polymer-modified microemulsions were used as new templates for the synthesis of inorganic particles, ranging from metals to complex crystallites, of …
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