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  • 1
    Electronic Resource
    Electronic Resource
    The sphere-rod transition of micelles of dodecyldimethylammonium bromide in aqueous NaBr solutions, and the effects of counterion binding on the micelle size, shape and structure (1984)
    Springer
    Colloid & polymer science 262 (1984), S. 409-417 
    Details
    ISSN: 1435-1536
    Keywords: dodecyldimethylammonium bromide ; rodlike micelle ; light scattering ; counter ion binding ; micelle size
    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 Micelle size and shape of dodecyldimethylammonium bromide have been determined by measurement of light scattering from its aqueous NaBr solutions. In water and in the presence of NaBr up to 0.07 M, the Debye plots give straight lines with positive slopes, and spherical micelles having molecular weight less than 30 000 are formed. At higher NaBr concentrations, the Debye plots decrease with increasing micelle concentration, indicating the aggregation of the primary spherical micelles into larger secondary micelles. The molecular weight and the radius of gyration of the secondary micelles increase with increasing NaBr concentration, and the relation between molecular weight and radius of gyration suggests that they are rodlike and flexible. Linear logarithmic relations between micelle molecular weight and ionic strength hold for spherical and rodlike micelles, respectively, and the threshold concentration of NaBr for the sphere-rod transition is located at 0.07 M. The spherical micelle of dodecyldimethylammonium ions has a size more than 20 surfactant ions larger in NaBr solutions than in NaCl solutions, and their rodlike micelle has a shorter length in NaBr solutions than in NaCl solutions, when compared at an identical aggregation number, indicating 2 more surfactant ions in its cross-section.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410261
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  • 2
    Electronic Resource
    Electronic Resource
    Rodlike micelles of dimethyloleylamine oxide in aqueous NaCl solutions, and their flexibility and size distribution (1984)
    Springer
    Colloid & polymer science 262 (1984), S. 497-506 
    Details
    ISSN: 1435-1536
    Keywords: dimethyloleylamine oxide ; rodlike micelles ; light scattering ; micelle size ; wormlike chain
    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 Angular dependence of light scattering from aqueous NaCl solutions of dimethyloleylamine oxide has been measured in the presence of NaCl from 5×10−4 M to 10−1 M at 25 °C. The molecular weight and radius of gyration of micelles increase with increasing micelle concentration and reach constant values, suggesting occurrence of the sphere-rod equilibrium dependent on the micelle concentration. With increasing NaCl concentration, rodlike micelles are larger in molecular weight and become longer. The micelles formed at NaCl concentrations higher than 10−3 M are nearly monodisperse when the micelle concentration is high. Rodlike micelles of dimethyloleylamine oxide in 10−2 M and 5 × 10−2 M NaCl solutions have molecular weights of 4,760,000 and 6,900,000, respectively, and behave as semi-flexible or wormlike chains. In 5×10−2 M NaCl they have a contour length of 5750 Å and a persistence length of 1760 Å. These micelle parameters correspond to the end-to-end distance of 3780 Å and the number of Kuhn's statistical segments of 1.64. The large aggregation number of the rodlike micelles is induced by the strong cohesion of long hydrocarbon chains in solution, and their flexibility is caused by the hydration of amine oxide groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01412047
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  • 3
    Electronic Resource
    Electronic Resource
    Sorption of ethanesulfonic acid by nylon-6 containing various numbers of end groups (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2393-2402 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: From the analysis of the permeation of 35S labeled ethanesulfonic acid, through nylon-6 films sorption isotherms were obtained. The films are characterized by their largely different content of carboxyl and amino end groups. It was found that the shape of the isotherm depends on the molar ratio of the two end groups: an S-shape curve for the film containing the carboxyl end group larger than the amino end group and a Langmuir-type curve for the film containing comparable numbers of end groups. These results were explained by the McGregor-Harris theory in which the acid dissociation constants of the two end groups in nylon were estimated experimentally.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160926
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  • 4
    Electronic Resource
    Electronic Resource
    A new synthetic route to polycarbonate (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 517-529 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A detailed study has been carried out on the new synthetic reaction of poly(p-xylylene carbonate) from potassium carbonate and p-xylylene dibromide by using a variety of crown ethers as a catalyst, which was recently found by the present authors. Crown ethers having 18-member ring showed the best catalytic property of the various crown ethers, and the reaction was conducted in various solvents at 50-160°C by using 18-crown-6-ether. Both the polymer yield and the molecular weight of the polymer increased in proportion to the amount of potassium carbonate, and they increased rapidly and reached constant values with increasing the concentration of 18-crown-6-ether. They also depended significantly upon the reaction temperature as well as the solvent used. A maximum yield with the highest molecular weight was obtained from the reaction at 100-120°C in diglyme solvent. The spectroscopic analysis of the polymer indicated that all the end groups of the resulting polymer had the structure of benzyl bromide. From these results, a plausible mechanism was proposed for the reaction. Similar reactions were also conducted by using several aliphatic dibromides, Br—(CH2)x—Br, in place of p-xylylene dibromide. The products were strongly dependent of the value of x: polycarbonate was obtained from dibromides with ≧4, and cyclic carbonates from dibromides with ≦3.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170221
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  • 5
    Electronic Resource
    Electronic Resource
    Molecular vibrations of irregular chains. II. Configurations of polydideuteroethylene (1966)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 1023-1029 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A simplified calculation of the CHD scissors vibration frequencies has been made for —(CHD)n— of various configurations. The correlation between the CHD scissors frequency and the local configuration has been established. On this basis the infrared absorption bands of poly-trans-CHD—CHD and poly-cis-CHD=CHD appearing in the region of 1350-1280 cm.-1 have been interpreted in greater detail.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1966.150040505
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  • 6
    Electronic Resource
    Electronic Resource
    Molecular vibrations of irregular chains. I. Analysis of infrared spectra and structures of polymethylene chains consisting of CH2, CHD, and CD2 groups (1966)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 1011-1021 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various samples of irregularly deuterated polyethylene were prepared and their infrared spectra were studied. The results support the previously proposed view that poly-trans-CHD=CHD or -cis-CHD=CHD obtained with Al(i-Bu)3-TiCl4 is an irregularly deuterated chain consisting of the CH2, CHD, and CD2 groups. A simplified calculation of the CHD scissors and CDH rocking vibration frequencies has been made for various model chains. The assignments of the CDH rocking vibration bands in the region of 700-500 cm.-1 have been given on this basis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1966.150040504
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