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Showing 1 to 20 of 23 for “"Cationic Surfactants"”.
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Phase Behavior and Structural Transitions in The Mixtures of Cationic Surfactants and Hydrophobic Counterions
… with certain geometry adsorb onto the surface of cationic surfactant micelles and they minimize the repulsion between the headgroups, so the charge density on the surface is reduced. As a result of this, the micelle spontaneously changes its morphology due to a new packing for the head groups. The …
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Application of Foam for Mobility Control in Enhanced Oil Recovery (EOR) Process
… (EOR) process. The performance of foam and surfactants was evaluated by systematic laboratory study. This includes the screening and evaluation of surfactant formulations for foam EOR process and the investigation of foam for mobility control at reservoir conditions. The adsorption of …
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Investigations on the Behaviour and Properties of Different Types of Unilamellar Vesicles
… of catanionic aggregation of oleate with some cationic surfactants, with a focus on the phase behaviour. Aqueous solution of 200 mM Na-oleate was isotropic micellar and was low viscous. Addition of octanol and geraniol as co-surfactants continuously lowered the mean spontaneous curvature on …
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Separation of algae from growth media by CGA flotation
… from growth media was investigated. Anionic, cationic and non-ionic surfactants were used to generate CGAs. Preliminary batch studies showed that two CGA flotation procedures could be successfully used for algae flotation. CGA flotation without pretreatment of algae was only successful using …
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Pseudostationary Phase for Solid Phase Extraction
… solution parameters were optimized and various cationic surfactants attached to cation exchangeable silica including silica modified with sulfopropyl groups and unmodified silica were investigated to reach sufficient sorbent hydrophobicity to capture EPA 16 priority polycyclic aromatic …
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A study of the removal of inorganic mercury by adsorptive bubble separation methods
… of 0.1 mg dm3 and in the presence of cationic surfactants in suitable excess.· Factors affecting removal of mercury (II) in batch, continuous and semi -continuous modes has been studied including the effect of gas flow rate, surfactant concentra and pH. In precipitate flotation …
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Surface chemical aspects of microbubble flotation
… is reduced with the addition of nonionic and cationic surfactants. On the other hand, the negative charge is increased with the addition of an anionic reagent. It has also been shown that the negative zeta potential of oil droplets increases with increasing hydrocarbon chain length.The effects …
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Crystal engineering, Bio Pharmaceutics and Cell biology of active pharmaceutical ingredient (drug) nanoparticles. Formation and cell interaction of hydrocortisone and prednisolone nanoparticles.
… was carried out on these nanosuspensions using cationic surfactants to obtain nanoparticles with different levels of surface positive charge as indicated by ¿-potential values. Dynamic light scattering (DLS) and transmission electron microscope (TEM) techniques were used to characterize the …
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Structure, Rheology and Optical Properties of Plasmonic Fluids
… detection and light trapping in photovoltaics. Cationic surfactants such as cetyl-trimethylammonium bromide have the ability to self assemble with metallic nanoparticles to form a corona or a double-layer vesicular structure. These structures upon further interaction with wormlike micelle …
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Surface Freezing in Surfactant/Alkane/Water Systems
… in mixed monolayers of a homologous series of cationic surfactants, the alkyltrimethyl ammonium bromides (CnTAB where n = 12, 14, 16, 18), as well as a range of non-ionic, zwitterionic and biological surfactants, have been investigated ellipsometrically with a range of n-alkanes (Cm where m = …
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Selectivity and detection in capillary electrophoresis
… organic modifiers, as well as a series of cationic surfactants are explored for the separation of a number of industrially important isomeric aromatic carboXylic acids². The separation was found to depend largely on the analyte1s geometry, degree of ionization as well as on the buffer pH …
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THERMODYNAMIC STUDIES OF BIS(QUATERNARYAMMONIUM) AND (N-ALKYL-) IONIC SURFACTANTS
… cyclododecyl c12-s-c12 (where s = 3,4,6) gemini surfactants containing dimethylammonium bromide head groups have been studied. The synthesized surfactants have been characterized according to their cmc, a, and surface coverage at the air-water interface. The cmc is found to decrease with …
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Interaction of azobenzene containing surfactants with plasmonic nanoparticles
… complexes between noble metal nanoparticles and cationic surfactants containing azobenzene units in their hydrophobic tail, employing absorption spectroscopy, surface zeta-potential, and electron microscopy. In the first part of the thesis, the formation of complexes between negatively charged …
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The Characterization of Cationic Pseudostationary Phases for Electrokinetic Chromatography
… between water and self-assemblies formed from cationic surfactants containing systematic variations in structure. One series of surfactants consisted of N-Alkyl-N-methylpyrrolidinium Ionic Liquid type headgroups. This is the first report of an ionic liquid surfactant used as the …
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The Characterization of Cationic Pseudostationary Phases for Electrokinetic Chromatography
… between water and self-assemblies formed from cationic surfactants containing systematic variations in structure. One series of surfactants consisted of N-Alkyl-N-methylpyrrolidinium Ionic Liquid type headgroups. This is the first report of an ionic liquid surfactant used as the …
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Oligomeric surfactants as novel type of amphiphiles : structure - property relationships and behaviour with additives
… From a molecular point of view, these oligomeric surfactants consist of simple monomeric cationic surfactant fragments coupled via the hydrophilic ammonium chloride head groups by spacer groups (different in nature and length). Properties of these cationic surfactant oligomers in aqueous solution …
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Surface Forces in Thin Liquid Films
… have been conducted in the presence of various cationic surfactants such as dodecylamine hydrochloride (DAH), and alkyltrimethylammonium chloride (CnTACl), electrolytes, and polymers. The results show that film stability and hence the kinetics of film thinning can be greatly improved by the …
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Emulsion Polymerization Using Switchable Surfactants
… on expanding the use of CO2-triggered switchable surfactants in emulsion polymerization of hydrophobic and hydrophilic monomers. Bicarbonate salts of the following compounds were employed as surfactants in the emulsion polymerization of styrene, methyl methacrylate (MMA) and/or butyl methacrylate …
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New Applications of Fluorescence Correlation Spectroscopy in Materials Science
… of molecules by FCS. Taking low-molecular-weight surfactants as an example it is shown that with the help of Coulomb interaction cationic surfactants can be labelled with anionic dye molecules and vice versa. Moreover, micelle formation is observed already at concentrations slightly below the …
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An investigation of chemiluminescent miniaturised analytical systems
… light produced. The incorporation of non-ionic surfactants into the analysis and their effect on the enhancement of the chemiluminescence emission intensity and the modification of electroosmotic flow is discussed.A quantitative analysis of codeine was then successfully performed using this …
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