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  • 1
    Electronic Resource
    Electronic Resource
    Orientational order in liquid normal alkanes: An investigation using gas-chromatographic data (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 485-495 
    Details
    ISSN: 1572-8927
    Keywords: Orientational order ; torsional oscillations ; n-alkanes ; gas chromatography ; thermodynamics ; Patterson ; Flory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Using retention voluems, obtained from gas-liquid chromatography with then-alkanesn-C28,n-C32, andn-C36 and the branched alkane squalane (2,6,10,15,19,23-hexamethyltetracosane) as the solvents and small branched andn-alkane molecules as solutes, excess chemical potentials were determined at 80, 100, and 120°C. From these data Flory'sX 12 parameter was calculated, which is related to differences in force field and in orientatinal order of the two compounds. After correction for end effects, theX 12 parameter in then-alkane solvents appeared to decrease with rising temperature and to increase with increasing chain length of then-alkane solvent. In addition,X 12 was dependent on the shape of the order-disturbing substance. These results all point to the presence of short-range orientational order in liquidn-alkanes, which was deduced to occur before from enthalpies of mixing by Patterson and from depolarized Rayleigh scattering by Bothorel. In addition, it is shown that theX 12 values are influenced by coupling of torsional oscillations of the molecules of the mixture components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01074866
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  • 2
    Electronic Resource
    Electronic Resource
    Evidence for coupling of torsional oscillations in alkane mixtures from thermodynamic data, obtained by means of gas chromatography (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 155-163 
    Details
    ISSN: 1572-8927
    Keywords: Flory ; Patterson ; alkanes ; torsional oscillations ; gas chromatography ; thermodynamics ; molar volumes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Data on the exchange-energy parameterX 12 in the Flory theory have been obtained previously from gas-chromatographic measurements for a number of normal and branched alkanes dissolved in the branched-alkane solvent squalane. These data are analyzed in the light of recently proposed theoretical concepts. It is shown that coupling of torsional oscillations of the components of the solutions (a phenomenon pointed to by Patterson) has a large influence on the values ofX 12, even in solutions of monomethyl-substituted alkanes. Analogous effects are observed in the molar volumes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00650523
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  • 3
    Electronic Resource
    Electronic Resource
    The principle of corresponding states for liquid normal and branched alkanes (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 475-483 
    Details
    ISSN: 1572-8927
    Keywords: Corresponding states ; characteristic data ; n-alkanes ; branched alkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Prigogine's principle of corresponding states for chain-molecule liquids was tested by the determination of the characteristic volumes, temperatures, and pressures of then-alkanes from hexane through dodecane and of branched hexanes, heptanes, and octanes, using the method of Patterson and Bardin. The characteristic parameterV * is shown to be influenced by steric hindrance in the molecule. The quantitiesV * andT * appeared to be slightly dependent on temperature;P * is independent of chain length in homologous series of normal and branched alkanes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01074865
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  • 4
    Electronic Resource
    Electronic Resource
    Thermodynamics of n-alkane systems and the solution theories of flory and prigogine (1973)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 11 (1973), S. 499-510 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The partial molar excess free enthalpies and enthalpies as well as the molar excess enthalpies of a number of n-alkane systems were reexamined within the scope of the polymer solution theory of Flory, Orwoll, and Vrij and that of Prigogine in the version after Delmas, Patterson, and Somcynsky. A semiempirical method was used to obtain characteristic n-alkane data, which obey the principle of corresponding states. By using these data (instead of those from the partition function after Flory and collaborators), a physically realistic interpretation of the excess free enthalpies over the whole concentration range is possible if the combinatorial contribution is purely athermal in nature. Both theories give an enthalpy interaction parameter near zero as expected, whereas neither a significant end effect nor an entropic interaction contribution is apparent from the analyses of the excess free enthalpies. The poor results obtained for the partial excess enthalpies and the enthalpies of mixing reflect the inadequacy of the partition functions on which these modern solution theories are based.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1973.180110308
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  • 5
    Electronic Resource
    Electronic Resource
    Determination of the Flory-Huggins χ parameter, the heat of dilution, and the excess heat capacity of some alkanes in polydimethylsiloxane by gas chromatography (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 12 (1974), S. 2065-2074 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The change in standard chemical potential of a number of alkanes on PDMS going from dilute solution to the perfect vapor ΔḠov was measured by gas chromatography over a large range of temperatures. The change in standard chemical potential of the alkane going from the pure liquid to the perfect vapor ΔḠov was calculated from fugacity data. These data were fitted separately to three Taylor's series expansions wherein the (partial) heat capacity of vaporization is zero, constant, and linearly dependent on temperature, respectively. On the basis of statistical and physical arguments it was concluded that the partial excess functions determined by gas chromatography should be described with a temperature-independent partial excess heat capacity.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.180121008
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  • 6
    Electronic Resource
    Electronic Resource
    Partial molar excess free enthalpies of n-alkenes in apiezon M and alkanes in squalane and polydimethylsiloxane, and the solution theories of prigogine and flory: An investigation by gas chromatography (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 401-417 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Partial molar excess free enthalpies (or excess chemical potentials) at infinite dilution were obtained over a large temperature range by gas chromatography. Data on n-alkenes in Apiezon M are interpreted by the Prigogine-Patterson theory; data on normal and branched alkanes in squalane and polydimethylsiloxane (PDMS) are discussed in terms of the Prigogine-Patterson theory and the solution theory of Flory, Orwoll, and Vrij. For the alkane-PDMS systems heats of dilution and partial excess heat capacity data are given.The aim of this work is to get some insight in the applicability of these solution theories to mixtures of fluids, the properties of which may slightly violate the basic assumptions of these theories. It is shown that orientational order in and a large cross-sectional chain diameter of the polymer solvent do not affect their applicability to the partical molar excess free enthalpies of apolar mixtures, whereas large dissimilarities between the force fields around the segments of the mixture components and/or dissimilar chain flexibilities detract from the applicability of these theories (alkanes in PDMS).Special attention has been paid to the effects of dissimilar size and shape of the segments of the mixture compounds on the magnitude of the interchange interaction parameter. It is shown that the multiple-connected segment model after Lichtenthaler et al. does not warrant a reliable combinatorial contribution. Comparison of the interaction parameters obtained for n-alkanes in n-alkanes, Apiezon, squalane, and polyisobutylene and for branched alkanes in squalane reveals that the magnitude of this parameter is affected by small end-effects due to the relative weakness of methyl-methylene interactions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180130216
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