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Wyniki wyszukiwania dla: IONIC SURFACTANTS
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Modeling the Influence of Salts on the Critical Micelle Concentration of Ionic Surfactants
PublikacjaWe show for the first time that a phenomenological, augmented volume-based thermodynamics (aVBT) model is capable to predict the critical micelle concentrations of ionic surfactants, including ionic liquids, with added salts. The model also adjusts for the type of salt added by including its molecular volume, which might form a connection to the Hofmeister effect. The other physico-chemically relevant quantities included in the...
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Predicting the critical micelle concentration of aqueous solutions of ionic liquids and other ionic surfactants
PublikacjaNiektóre ciecze jonowe, szczególnie te będące kombinacją organicznego i nieorganicznego jonu, wykazują strukturalne podobieństwo do surfaktantów. Krytyczne stężenie micelizacji jest podstawowym parametrem w chemii powierzchni i nauce o koloidach. Parametr ten został zmierzony dla wielu cieczy jonowych, jednakże ze względu na ogromną ilość możliwych kombinacji anionów i kationów jego eksperymentalny pomiar dla wszystkich struktur...
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Aggregation of nonionic surfactants in imidazolium ionic liquids
PublikacjaMicellar aggregation of surfactants in aqueous solutions has been described in terms of the balance between dispersive interactions of the hydrocarbon part of the amphiphilic molecule, and the hydration and electrostatic repulsive effects of hydrophilic head group. Changing the interactions by replacing water with another polar solvent, such as amides or glycols, has been studied to a smaller extent (Singh, Saleem et al. 1980;...
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Determination of Surfactants in Environmental Samples. Part III. Non-Ionic Compounds
PublikacjaNon-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of such agents. Typically, non-ionic compounds found applications in households and industry during formulation...
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Effect of the addition of non-ionic surfactants on the emission characteristic of direct current atmospheric pressure glow discharge generated in contact with a flowing liquid cathode
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The improvement of the analytical performance of direct current atmospheric pressure glow discharge generated in contact with the small-sized liquid cathode after the addition of non-ionic surfactants to electrolyte solutions
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Dual functionality of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids: surfactants with catalytic function
PublikacjaA series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6–C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst...
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Studies on micellar aggregation of nonionic surfactants in imidazolium liquids
PublikacjaA number of imidazolium ionic liquids, with 2-8 carbon atoms in cation alkyl chains, and tetrafluoroborate, hexafluorophosphate, bis(trifluoromethylsulfony)imide and trifluoromethanesulfonate anions, were characterized for their ability to support micellar aggregation of nonionic surfactants in binary solutions.
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Analytics of Surfactants in the Environment: Problems and Challenges
PublikacjaSurfactants (surface active agents = SAAs) are a group of compoundswith specific physicochemical properties (amphiphilicity,solubility in polar and nonpolar liquids, ability to form micelles,adsorption at phase boundaries).1,2 Because of their properties,surface-active compounds are widely applied in industry and thehousehold (e.g., in detergents, personal-care products, paints,pesticides, petroleum products). As their applications...
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Surfactants: a real threat to the aquatic geoecosystems of lobelia lakes
PublikacjaLobelia lakes are valuable elements of the natural environment. They are characterised by low trophy, mainly in-forest location and a high transparency of water. However, similarly to other surface waters, they are subjected to increasing anthropogenic pressures, a good indicator of which is the level of surfactants, also called surface-active agents (SAAs). The aim of the study was to evaluate the intensity of anthropogenic pressures...
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New methodology for determination cationic surfactants in liquid environmental samples
PublikacjaBecause of their specific physical and chemical properties (e.g. amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate. Mainly,...
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Selected anionic and cationic surface active agents determined in river sediments – the Klodnica catchment
PublikacjaSurface active agents (SAAs) are specific compounds that contain hydrophilic/ hydrophobic group in their molecules named as amphiphilic structures. According to charge on the hydrophilic part of surfactants they can be classified into three main groups: anionic, cationic and non-ionic compounds. Due to the amphiphilic structure of SAAs they have specific properties (e.g. ability to adsorption at different surfaces, reduction of...
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DETERMINATION OF SURFACTANTS IN ENVIRONMENTAL SAMPLES - PART I. CATIONIC COMPOUNDS = Oznaczanie Surfaktantów W Próbkach Środowiskowych. Część I. Związki Kationowe
PublikacjaCompounds from the group of cationic surfactants are widely applied in household, industrial, cleaning, disinfectant, cosmetic and pharmaceutical products as their specific properties (antimicrobial, emulsifying, anticorrosion, softening). After use, cationic surfactants are disposed to wastewater-treatment plants and finally with effluent water to surface waters due to their incomplete degradation. Moreover, they can freely circulate...
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First evaluation of wastewater discharge influence on marine water contamination in the vicinity of Arctowski Station (Maritime Antarctica)
PublikacjaIn Antarctica,waste is generatedmainly during scientific research programmes and related logistics. In this study, the impact ofwastewater on the western shore of Admiralty Baywas investigated during austral summer in 2017 and 2019. A range of physicochemical parameters and the presence of selected trace metals, formaldehyde and different groups of surfactants were determined in wastewater coming from Arctowski Station and in nearby coastal...
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Drinking water safety evaluation in the selected sub-Saharan African countries: A case study of Madagascar, Uganda and Rwanda
PublikacjaIn the sub-Saharan region of Africa, access to safe drinking water remains limited in many countries. This study provides an overview of the quality of surface water and groundwater in rural and peri-urban areas of Madagascar, Uganda, and Rwanda. Selected physico-chemical parameters, inorganic species (including inorganic ions), and organic pollution indicators, such as total organic carbon, non-ionic surfactants, cationic surfactants, anionic...
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Morphology control through the synthesis of metal-organic frameworks
PublikacjaDesignable morphology and predictable properties are the most challenging goals in material engineering. Features such as shape, size, porosity, agglomeration ratio significantly affect the final properties of metal- organic frameworks (MOFs) and can be regulated throughout synthesis parameters but require a deep under- standing of the mechanisms of MOFs formation. Herein, we systematically summarize the effects of the indi- vidual...
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Effect of alkyl sulfate on the phase behavior of microemulsions stabilized with monoacylglycerols
PublikacjaIn this study the effect of an anionic surfactant (sodium dodecyl sulfate SDS) and oils (hydrocarbons: C12-C16) on the formation and phase behavior of the systems of oil/monoacylglycerols (MAG):SDS/propylene glycol/water has been investigated. The effects of the surfactant mixture on the phase behavior and the concentrationof water or oil in the systems were studied at three temperatures (50, 55, 60 C). Electrical conductivity...