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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 30 (1992), S. 587-590 
    ISSN: 0887-6266
    Keywords: poly(allylammonium) cation, counterion binding to ; ion activity in aqueous poly(allylamine) hydrochloride, binding and selectivity in ; polyelectrolytes, counterion binding and selectivity in solutions of ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Chloride ion activity coefficients in aqueous solutions of poly(allylamine) hydrochloride (PAA · HCl) have been determined both in the absence and the presence of simple salts. Without added salt, the activity coefficient depends on the polymer concentration. With added salt, the binding of added counterions by PAAH+ is evaluated from the release of chloride ion. The extent of interaction between counterions and PAAH+ at a given polymer concentration decreases in the order SO42- ≫ ClO4- 〉 NO3- 〉 Cl- 〉 Br- 〉 I-. This order of counterion selectivity agrees with the previous estimation of potentiometric titrations. The result shows that the hydration of the counterion, as well as its charge, plays an important part in counterion binding to the polyion.
    Additional Material: 3 Ill.
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  • 2
    ISSN: 0887-6266
    Keywords: association of hydrophobic counterions in aqueous poly(allylammonium) chloride ; hydrophobicity and steric effect of alkyl groups on association of p-n-propylbenzenesulfonate and p-iso-propylbenzenesulfonate ions ; poly(allylammonium) cation ; conformation change and precipitation of ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The hydrophobic association behavior of p-propylbenzenesulfonate ions (n-PBS- and iso-PBS-) around poly(allylammonium) cation (PAAH+ was studied by absorption and 1H nuclear magnetic resonance (NMR) spectroscopy. In the presence of PAAH+Cl-, the broadening (hypochromism) of absorption band of PBS- were observed. In addition, all 1H NMR signals of PBS- exhibited up-field shift which resulted from the intermolecular ring current shift. These results indicate the hydrophobic association of negative PBS- around PAAH+. The hydrophobic association arises from the accumulation of counterions around the polyion, and is stabilized by the hydrophobic interaction between propyl groups and the stacking interaction between benzene rings. The association of iso-PBS- ions is rather weaker than that of n-PBS-, suggesting that the steric hindrance of isopropyl groups prevents an effective association of hydrophobic counterions. Furthermore, through viscosity and Cl- activity measurements, it was found that the binding of associated PBS-,s to PAAH+ causes the change of its surroundings to hydrophobic character and its conformation. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
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  • 3
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Monoclonal antibodies were produced against a cell-cell adhesion (contact site A) glycoprotein of Dictyostelium discoideum, isolated by preparative gel electrophoresis. The glycoprotein was recovered by electroelution from a polyacrylamide gel strip and used for the production of monoclonal antibodies. Four of the five antibodies obtained bound specifically to the protein moiety of the contact site A glycoprotein. The specificities of the antibodies were in striking contrast to those of antibodies raised against the contact site A glycoprotein purified by Triton X-114 phase separation and DEAE chromatography. The majority of the latter antibodies recognized the carbohydrate moiety of the contact site A glycoprotein and cross-reacted heavily with other membrane glycoproteins.
    Additional Material: 3 Ill.
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  • 4
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Membranes obtained from polymers, quaternized poly[3-(N′,N′-dimethyl) aminopropylacrylamide-co-acrylonitrile]s, showed selective separation of water from aqueous ethanol solution by pervaporation. The separation factor toward water reached over 15,000. Membrane performance showed a good correlation to membrane polarity. Differential scanning calorimetric melting endotherms of the water-swollen membranes were studied to clarify the state of water in the membranes. The results suggested that there are two states of water in the membrane: bound and free. The higher the fraction of bound water in the membrane, clearly, the more preferentially was water permeated.
    Additional Material: 8 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 28 (1990), S. 233-240 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Potentiometric titration in various 1-1 salt solutions was carried out to study the dissociation behavior of the poly(allylammonium) cation (PAAH+). The titration curves show that proton release from cationic PAAH+ is markedly suppressed by addition of simple salt and depends on the counterion species. From an analysis of the titration curves it is found that the electrostatic free energy change ΔGel upon the proton release is negative in all systems examined, and its absolute value decreases with increasing ionic strength of the medium. Also, at a constant added salt concentration (0.1 mol L-1) ΔGel depends significantly on the counterion species added and increases in the order $\[ {\rm ClO}_{\rm 4}^ - 〉 {\rm NO}_3^ - 〉 {\rm Cl}^ - 〉 {\rm Br}^ - 〉 {\rm SCN}^ - 〉 {\rm I}^ - . \]$ The value of ΔGel correlates well with the electron donor constant En of the counterions. The dissociation behavior of PAAH+ is discussed in terms of electrostatic interaction among the ionized groups on the chain, the charge shielding effect, and the ion-solvent interaction of the added counterions.
    Additional Material: 5 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Communications in Applied Numerical Methods 6 (1990), S. 535-542 
    ISSN: 0748-8025
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The boundary integral formulation for unsteady thermal stresses in three-dimensional quasi-static problems is proposed. It is shown that three-dimensional unsteady thermal stress problems can be solved easily without the volume integral by means of the thermoelastic displacement potential and the boundary-element method. It is also shown that the time integral can be easily carried out analytically. In order to investigate the accuracy of this method, unsteady thermal stress distributions for a cube are obtained.
    Additional Material: 3 Ill.
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