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  • 11
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 16 (1977), S. 33-41 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the presence of sodium poly(L-glutamate) at pH = 7.5 the dye pseudoisocyanine in dilute aqueous solution (Cd = 1.10 × 10-5 M) and low P/D values exhibits an absorption spectrum with a very sharp red-shifted J-band. Under the same conditions circular dichroism (CD) in the visible region is observed with an extremely sharp peak at the position of the J-band. At pH = 4.6, where the polypeptide is in the α-helix conformation, no such J-band is observed and no CD spectrum can be detected at the same P/D values. CD spectra in the uv range demonstrate that the occurrence of the dye-polypeptide complex which gives rise to the J-band at slightly alkaline pH is not accompanied by a conformational transition of the polypeptide towards the α-helical form.
    Additional Material: 4 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 14 (1975), S. 1313-1313 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract.
    Type of Medium: Electronic Resource
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  • 13
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electric permittivity of alfalfa virus particles in buffer solutions of three different concentrations at pH 7 was studied between 10 kHz and 100 MHz. The experimental results could be described with one single dispersion curve of the Cole-Cole type characterized by a concentration independent specific dielectric increment and mean relaxation time. The results were interpreted semi-quantitatively in terms of counterions-atmosphere polarizability, neglecting counterion repulsion.
    Additional Material: 1 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 12 (1973), S. 655-674 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ultraviolet absorption, linear dichroism, circular dichroism, and oriented circular dichroism of collagen are reported and the spectra are resolved into a self-consistent set of bands in accord with exciton theory. The parallel band at 200 nm has 40% of the π → π* intensity; the perpendicular band is placed at 189 nm yielding a splitting of 2700 cm-1. The circular dichroism is resolved into two Gaussians at λ∥ and λτ (rotational strengths +14 × 10-40 and -32 × 10-40 esu2. cm2) plus a large non-Gaussian (“helix”) band with ampplitude -25,000° at 201 nm. These data appear to be in reasonably good accord with recent calculations.Measurements of the absorption, linear dichroism and circular dichroism of polyproline I and II are also reported and are resolved into their component bands. Polyproline I is in good accord with exciton theory, whereas polyproline II remains unsatisfactory.
    Additional Material: 11 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 23 (1957), S. 241-245 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: It seems that the dielectric properties of high polymer solutions may be partially attributed to an interaction between the macromolecules and the molecules of solvent, if the latter is polar. The study of the variations of the static dielectric constant with the temperature yields interesting data. By applying a model analogous to that proposed by Fröhlich for pure liquids to a dilute solution of a polar macromolecule in a polar solvent, a correlation factor (g) may be defined if the deformation polarization is considered macroscopically through the refractive index of the solutions. This treatment is valid as well in the case of rigid macromolecules as in the case where these chains are decomposed in statistical segments. The example of a 2% solution of polybutylmethacrylate in toluene shows that this effect indeed exists. The study of these properties, which is now going on, will show if a relation exists between the factor g for different solutions of high polymer in different solvents, particularly with respect to an eventual precipitation temperature.
    Notes: Il semble possible d'attribuer partiellement les propriétés diélectriques de solutions de hauts polymères à une interaction entre la macromolécule et les molécules du solvant, si ce dernier est polaire. L'étude de la variation de la constante diélectrique statique avec la température peut alors apporter des renseignements intéressants. Appliquant à la solution diluée d'une macromolécule polaire dans un solvant polaire, un modèle analogue à celui proposé par Fröhlich pour les liquides purs, on peut définir un facteur de corrélation (g) si l'on tient compte de la polarisation de déformation d'une façon macroscopique à travers l'indice de réfraction de la solution. Le raisonnement est valable aussi bien pour le cas où l'on considère la macromolécule comme un tout plus ou moins rigide que pour celui où on la décompose en chaǐnons statistiques. L'exemple d'une solution à 2% de polyméthacrylate de butyle dans le toluène montre que l'effet existe. I'étude de ces propriétés, commencée depuis peu au laboratoire, aura e.a. pour but de voir s'il existe une relation entre le facteur g pour différentes solutions de hauts polymères dans différents solvants, notamment par rapport à une éventuelle température de précipitation.
    Additional Material: 1 Ill.
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  • 16
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 56 (1962), S. S23 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 14 (1976), S. 773-781 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dielectric relaxation behavior of three sodium polyphosphates with different but low degrees of polymerization in aqueous solution (without salt) has been investigated between 8 kHz and 100 MHz. The highest molecular weight sample (DP 338) exhibits two dispersion regions as is generally observed with synthetic polyelectrolytes at higher degrees of polymerization and is interpreted, according to the theory of van der Touw and Mandel, by attributing a certain flexibility to the polymer chain. The experimentally determined relaxation time of the high-frequency dispersion is in fair agreement with the theoretically calculated value. For the lowest molecular weight sample (DP 112) the experimental results can best be described by a single dispersion curve pointing to a rigid, more or less stretched, conformation of the polyion in agreement with theoretical predictions. For the sample of intermediate molecular weight (DP 198) the situation is borderline as it is possible to describe the relaxation behavior by either one or two dispersion regions; it is, however, concluded from an analysis of the dielectric results that the average conformation is rather extended, but not completely rigid.
    Additional Material: 1 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 2 (1964), S. 3771-3780 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Cu(II) chelate of polymethacrylic acid was investigated. Viscometric, electrophoretic, and spectrophotometric evidence is shown to confirm the potentiometric results reported previously which indicated the binding of two carboxylic groups by one Cu(II) ion.
    Additional Material: 8 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 2 (1964), S. 1879-1891 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The potentiometric behavior of polymethacrylic acid is discussed in terms of a conformational transition. A thermodynamic treatment of this transition is presented. The titration curve of polymethacrylic acid is analyzed in a detailed way and quantitative information regarding the transition is obtained.
    Additional Material: 5 Ill.
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  • 20
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 2 (1964), S. 2883-2899 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The calculation of formation curves of metal-polyacid complexes from titration curves is discussed. The interaction of bivalent ions of Cu, Cd, Zn, Ni, Co, and Mg with poly(methacrylic acid) is investigated by this method. These metals seem to form complexes involving two carboxylate groups for each ion in a large domain of pH values. Formation constants for these complexes are given which decrease according to the order indicated above.
    Additional Material: 14 Ill.
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