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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 193-202 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Potentiometric titrations in water of high-molecular-weight partly hydrolyzed polyacrylamides were analyzed by the Lifson - Katchalsky rodlike model. A fair concordance was found between theory and experimental curves with pK0 of acid functions of about 4.75 when 0 〈 τ 〈 0.49. Two methods were derived to calculate the parameter n of the extended Henderson-Hasselbach equation by using a series expansion of pKa vs. α, not yet reported in the literature. A new equation for n was established and comparison between two sets of values of n, obtained by using the theoretical ΔpK curves and series expansion is discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 659-672 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of ionization (α) and added salts (NaCl, CaCl2, MgCl2) on the dimensions of commercially available high-molecular-weight polyacrylamides (Mw ≃ 4 × 106), hydrolyzed at various extents (0.04 〈 τ 〈 0.49) and which have been characterized, was investigated by viscosity and light-scattering measurements performed at 25°C. The data point with evidence to the strong dependence of the chain dimensions on the charge density (ατ) and the effect of the nature and concentration of added salts. From a practical point of view it is shown that there is no advantage to using too highly hydrolyzed samples (τ 〉 0.45) in media containing large amounts of salts that lead to precipitation of polymers, especially in the presence of divalent ions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 77-87 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction between polyelectrolytes and Acridine Orange (AO) has been investigated in the case of poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), and a polycondensate between 1,3-benzene disulfonyl chloride and L-lysine (PLL) by visible absorption and fluorescence spectroscopy. The influence of both polymer ionization and polymer/dye ratio (P/D) on the spectral behavior of the bound dye has been studied. The stacking tendency of AO is found lower in the presence of PLL under compact conformation (in an ionization range depending on the nature of the counterion) with correlated enhancement of the green fluorescence of the monomeric species of the bound dye. The disappearance of the green fluorescence and the dimerization of bound AO are directly related to the increased flexibility of polyion chains upon ionization. Some analogy is found between the behavior of bound AO in the presence of very compact PLL chains and that reported for AO in the presence of native DNA, which might be due to specific interactions responsible for a kind of “intercalation” of the monomeric bound dye.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 4011-4020 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of polymer conformation, polymer concentration, and added salt concentration on the quantum yield φ of Auramine O (AuO) is discussed in connection with dialysis equilibrium data. The quantum yield per bound dye molecule (φ/q) assumes different values which are related principally to solvation changes in the environment of the binding sites. Binding to globular compact a states results in high φ/q, whereas low φ/q (of the order of magnitude of φ of free AuO) are observed for the binding to expanded solvated b states. The quantum yield of bound AuO is therefore affected by the organic nature of the environment, but shows little or no relation to the amount of bound dye molecules.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1367-1373 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the induced Cotton effects in the visible region of the absorption bands of acridine orange in the presence of a nonstereoregular α-carboxylic polysulfonamide (PLL) can be attributed to stacked bound dye molecules, irrespective of the conformation of the polymer. The existence of an ordered structure seems to be unnecessary for such an induction.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 327-336 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction between 2-p-toluidinylnaphthalene-6-sulfonic acid (TNS), a hydrophobic fluorescent probe, and poly(2-vinylpyridinium) polyions (PVP) has been investigated by fluorescence spectroscopy. Both the effect of the charge and the concentration of PVP on the fluorescence behavior of TNS indicate that interaction between TNS and hydrophobic sites present in the PVP chain is responsible for the observed phenomena. It is shown that PVP which exists with predominant hydrophobic regions leads to TNS fluorescence, but some residual charge must be present to facilitate the penetration of the dye into the hydrophobic regions. Various situations existing in some polyelectrolyte systems are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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