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  • Inorganic Chemistry  (6)
  • aggregation  (3)
  • cationic surfactants  (3)
  • micelles  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 275 (1997), S. 396-399 
    ISSN: 1435-1536
    Keywords: Key words Micelles ; hydration ; hydroxide surfactants ; cationic surfactants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The hydration of dodecyltrimethylammonium hydroxide (DTAOH) micelles was determined by viscosity measurements, giving 39.2±7.0 water molecules per micellized dodecyltrimethylammonium ion. This result is lower than the hydration of DTAB micelles, which is about 65. This difference may be due to the effect of the electrorestrictive structure-making hydroxide ion on the hydration of the alkyltrimethylammonium head group, in comparison with the less hydrated structure-breaking bromide ion.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1435-1536
    Keywords: Key words Hydroxide surfactants ; micelles ; partial molar volume ; Dodecyltrimethylammonium hydroxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The partial molar volume of dodecyltrimethylammonium hydroxide in water and aqueous NaOH solutions was measured. The addition of NaOH did not affect either the micellized or the unmicellized molecules. The expansion on micellization is much larger than in dodecyltrimethylammonium bromide systems, which reflects the stronger ionization of the hydroxide surfactant micelles, when compared with that of the bromide amphiphile.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 273 (1995), S. 959-966 
    ISSN: 1435-1536
    Keywords: Hydroxide surfactants ; critical micelle concentration ; aggregation ; cationic surfactants ; micelle charge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The aggregation of dodecyltrimethylammonium hydroxide (DTAOH) aqueous solutions has been studied by several methods. It is stepwise and four critical points were found. AtC T=(2.51±0.10)×10−4 mol · dm−3 the surface excess becomes zero, atC T=(1.300±0.041)×10−3 mol · dm−3 small aggregates from, which grow with concentration. AtC T=(1.108±0.010)×10−2 mol · dm−3 true micelles form (CMC) and at (3.02±0.28)×10−2 mol · dm−3 the structure of micelles probably changes affecting their properties. The DTAOH micelles are highly ionized (α=0.8) at the CMC, and decreases to reach very small values when the total concentration increases.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 274 (1996), S. 854-859 
    ISSN: 1435-1536
    Keywords: Hydroxide surfactants ; critical micelle concentration ; aggregation ; cationic surfactants ; counterion effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The aggregation of dodecyltrimethylammonium hydroxide (DTAOH) in aqueous NaOH solutions was studied as a function of NaOH concentration. As in NaOH-free DTAOH aqueous solutions, the surfactant underwent a stepwise aggregation mechanism. Changes in the structure of aggregates produced an increase of the concentration at which premicellar aggregates could solubilize hydrophobic dyes and also in the concentration at which hydroxide inons join the aggregates.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 274 (1996), S. 669-677 
    ISSN: 1435-1536
    Keywords: Dodecanephosphonic acid ; dodecyltrimethylammonium hydroxide ; mixed micelles ; critical micelle concentration ; aggregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The aggregation of aqueous dodecylphosphonic acid (DPA) and dodecyltrimethylammonium hydroxide (DTAOH) mixtures was studied by several methods. The behavior of DPA-rich mixtures is close to that of pure DPA. This is probably due to the preservation of the hydrogen-bonded structure of the micellar headgroup layer. The behavior is almost ideal. Betweeny DPA =0.5 and 0.33 (y DPA being the mole fraction of DPA in the surfactant mixture), the hydrogen-bonded structure of the micellar headgroup layer is destroyed. A sort of “micellar azeotrope” is formed, and the maximum of non-ideal interaction between the two surfactants is attained aty DPA =0.4. Fory DPA 〈0.33 the system behaves as a common mixture of a cationic surfactant and a non-ionic one (DPA.2LTA). There is a phenomenon of counterion “condensation” on aggregates at concentrations over the CMC.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 275 (1997), S. 604-607 
    ISSN: 1435-1536
    Keywords: Key words Solubilization ; hydroxide surfactants ; styrene ; monomers ; micelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The solubilization of styrene molecules in aqueous dodeciltrimethylammonium Hydroxide (DTAOH) solution was studied by UV-Vis spectroscopy. In short, fully ionized DTAOH aggregates the styrene molecules in the micelle double layer, oriented with their vinyl group to the micelle core and the aryl ring to the intermicellar solution. At increased surfactant concentration, when the aggregates incorporate counterions in their Stern layer, the orientation is maintained, but styrene molecules gradually penetrate into the micelle core as the micelle size and degree of counterion union increased, until they were completely immersed in the hydrocarbon core of rod-like micelles.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1435-1536
    Keywords: Key words Catanionic surfactants ; evaporation rate ; electrobalance ; premicelles ; dodecyltrimethylammonium n-dodecanephosphonates ; micelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  Electrobalance evaporation rate measurements were used to measure solute weights in the aqueous catanionic system monododecyltri-methylammonium-n-dodecanephos-phonate. At very low concentration premicelles composed of ion pairs between 3.6 and 7 were found, which increased with concentration. Above the cmc the aggregates increased in size with concentration much more rapidly. Aggregates had 54 ion pairs at the higher studied concentration (6×10-3 mol dm-3). This value agrees with literature data of other similar systems. Since the system is probably polydisperse and the evaporation rate method gives number average weights, the true aggregation numbers are probably higher than those found. In this system the cmc did not indicate the starting point of aggregation, but a change in the aggregates structure and growing regime.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 294 (1958), S. 224-232 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die partielle Hydrolyse von POCl3 führt bei stöchiometrischen Verhältnissen zur Dichlorphosphorsäure. Diese Säure und einige ihrer Salze konnten rein dargestellt werden. Bei der weiteren Hydrolyse war die Monochlorphosphorsäure nicht zu fassen, da unter den gewählten Reaktionsbedingungen Kondensationsreaktionen zu Derivaten von Polyphosphorsäuren führten. Die Hydrolyse von PCl3 lieferte trotz Variation der Bedingungen phosphorige bzw. diphosphorige Säure als Hauptprodukte. Daneben tritt eine Disproportionierung in POCl3 und P4O ein. Der Reaktionsmechanismus wird diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation, Crystal Structure, and Temperature Dependence of the Homogeneity Range of the Phase Ca2-xAs1-xBr1+x and Thermal Behaviour of Ca3AsBr3The phase (Ca2-x□x)(As1-xBr1+x) (yellow, NaCl type lattice, x ≙ degree of substitution) was prepared from “Ca3As2” and CaBr2 in different molar ratios in steel ampoules under argon at 900 and 950°C resp. The lattice constant as a function of the composition, the homogeneity range, and dependence of the bromine rich phase boundary on the temperature were determined. The structure was deduced from single crystal X-ray investigation and density measurements at different compositions.The thermal behaviour of Ca3AsBr3 (colourless, isotypic to Mg3NF3, prepared at 850°C) was studied by annealing samples in molybdenum ampoules under argon in the temperature range 900-1250°C and by differential thermal analysis.From the experimental results a section of the phase diagram Ca3As2-CaBr2 was constructed.
    Notes: (Ca2-x□x)(As1-xBr1+x) (gelb, NaCl-Typ, x ≙ Substitutionsgrad) stellte man aus „Ca3As2“ und CaBr2 (unterschiedliche Molverhältnisse) in Stahlampullen unter Argon bei 900 bzw. 950°C dar. Die Abhängigkeit der Gitterkonstante von der Zusammensetzung, der Homogenitätsbereich und die Temperaturabhängigkeit der bromidreichen Phasengrenze wurden ermittelt. Die Struktur bestimmte man durch die röntgenographische Einkristalluntersuchung und durch Dichtemessungen bei unterschiedlichen Zusammensetzungen.Das thermische Verhalten des Ca3AsBr3 (farblos, Mg3NF3-Typ, dargestellt bei 850°C) untersuchte man durch Erhitzen von Proben in Molybdänampullen unter Argon im Temperaturbereich 900 bis 1250°C und durch differenzthermoanalytische Messungen.Mit den experimentellen Ergebnissen wurde ein Ausschnitt aus dem Zustandsdiagramm Ca3As2-CaBr2 konstruiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 435 (1977), S. 98-102 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chalcogenolates and their Derivatives. I. Syntheses and Properties of Ionic ChalcogenophenolatesThe syntheses and properties of ionic chalcogenophenolates are described. Using liquid ammonia as solvent the alkali chalcogenophenolates M[EPh] (M = Na, K; E = Se, Te; Ph = C6H5) have been synthesized via reduction of the diphenyl dichalcogenides with alkali metals. Similarly, the tetraphenylphosphonium chalcogenophenolates [Ph4P][EPh] (E = S, Se, Te) have been obtained by reacting alkali chalcogenophenolates with tetraphenylphosphonium chloride.
    Notes: Darstellung und Eigenschaften salzartiger Chalkogenolate werden beschrieben. In verflüssigtem Ammoniak als Lösungsmittel lassen sich die Alkalichalkogenophenolate M[EPh] (M = Na, K; E = Se, Te; Ph = C6H5) durch Spaltung der Diphenyldichalkogenide mit Alkalimetallen, die Tetraphenylphosphoniumchalkogenophenolate [Ph4P][EPh] (E = S, Se, Te) durch doppelte Umsetzung der Alkalichalkogenophenolate mit Tetraphenylphosphoniumchlorid erhalten.
    Type of Medium: Electronic Resource
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