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  • 1
    ISSN: 1520-5002
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Maschinenbau
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 12875-12882 
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 97 (1993), S. 6920-6923 
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Journal of applied electrochemistry 16 (1986), S. 41-52 
    ISSN: 1572-8838
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract Interactions between cation exchange membranes and large organic cations have been studied; namely (1) adsorption and electrodialytic desorption of cationic surface active agents, and (2) change in transport properties of the membranes by adsorption. N-dodecyl pyridyl compounds, such as N-dodecyl pyridinium bromide (C12-Py), N-dodecyl dipyridyl bromide (C12-Dipy) and N-dodecyl tripyridyl bromide (C12-Tripy) were used for the adsorption and electrodialytic desorption; and for the study on the change in transport properties of membranes, N-dodecyl pyridinium chloride, C12-Py, C12-Dipy, C12-Tripy and hexadecyl trimethylammonium chloride were used. It was confirmed that the higher the molecular weight of the cation the longer the time required to reach adsorption equilibrium, and that the amount of adsorption exceeded the ion-exchange capacity of the membrane. After equilibrium was attained, electrodialytic desorption from the membranes was difficult. The adsorption or ion-exchange of large organic cations was effective to the permselectivity of the cation exchange membrane to the sodium ion in electrodialysis of a solution of sodium chloride and calcium chloride. The relationship between the permselectivity and the properties of the cations was examined.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Colloid & polymer science 256 (1978), S. 62-77 
    ISSN: 1435-1536
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Wechselwirkung von Ionenaustauschermembranen mit grenzflächenaktiven Stoffen wird durch Elektrodialyse untersucht. Der elektrische Widerstand der Membranen steigt während der Elektrodialyse beträchtlich an, wenn die grenzflächenaktiven Ionen entgegengesetzte Ladungen wie die Austauschergruppen der Membranen haben. Es wurde gefunden, daß 1. die Adsorption oder der Ionenaustausch der grenzflächenaktiven Ionen an der Membran beträchtlich durch das elektrische Feld verstärkt wird; 2. die Zunahme des elektrischen Widerstandes groß ist, wenn das grenzflächenaktive Ion ein hohes Molekulargewicht hat und möglichst sperrig ist; 3. die Widerstandsänderung merklich von der Art der Membran beeinflußt wird. Auf Grund dieser Versuche wurde die Möglichkeit geprüft, die Zunahme des Membranwiderstandes bei Gegenwart grenzflächenaktiver Stoffe durch Adsorption von Polyelektrolyten zu reduzieren.
    Notizen: Summary Interaction between ion exchange membranes and surface active agents was observed by electrodialyzing the salt solution containing the surface active agent. The behavior of the electric resistance of the membrane during the electrodialysis, the current efficiency and the adsorbed or ion-exchanged amount and the permeated amount of the surface active agent were observed. Generally, the electric resistance of the membrane during the electrodialysis increased remarkably when the ionic surface active agent having the opposite charge to ion-exchange groups of the membrane was contained in the solution. And the correlation of the behavior of the electric resistance of the membrane to the electrodialysis condition, species of surface active agents and species of membranes was mainly observed. Results were as follows. 1) The adsorption' or ion-exchange of ionic surface active agent on the membrane was remarkably emphasized by the electric field. 2) The degree of the increase in the electric resistance of the membrane was remarkable when the surface active agent had the high molecular weight and the bulky molecular structure. 3) The degree of the increase in the electric resistance was remarkably various according to species of the membranes. From these results, a protecting method for the change of these membrane properties was examined. When the ion exchange membrane was treated with the polyelectrolyte solution having the opposite charge to ion exchange groups of the membrane, the increase in the electric resistance by ionic surface active agent was depressed. Generally, though the change of electrodialysic properties of the membrane by the ionic surface active agent was remarkable in the membrane having the tight structure, the change of the properties of the membrane having the tight structure was easy to be protected by the polyelectrolyte treatment. Though the ionic surface active agent having the bulky molecular structure made the properties of the membrane change remarkably, the change of the properties of the membrane by the bulky surface active agent could be easily protected by the polyelectrolyte treatment.
    Materialart: Digitale Medien
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  • 6
    ISSN: 0003-3146
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Um bei Kationen-Austauschmembranen eine dauerhafte Selektivität für die Durchlässigkeit von einwertigen Kationen zu erzielen, wurde eine Polyethylenimin-Schicht auf der Membranoberfläche durch Säureamidbindung zwischen Polyethylenimin und den —SO2Cl-Gruppen einer Styrol-co-Divinylbenzol-Membran erzeugt. Nach der Reaktion wurden die im Inneren der Membran verbleibenden —SO2Cl-Gruppen durch Tauchen in wäßrige Natronlauge hydrolysiert.Die so gewonnenen Kationen-Austauschmembranen wurden mittels Elektrodialyse von Seewasser hinsichtlich ihrer Selektivität für die Durchlässigkeit von einwertigen Kationen, ihres elektrischen Widerstandes, ihrer Stromleistung und ihrer überfüh-rungszahlen für Natrium-Ionen untersucht. ATR-IR-Messungen auf der Membran-oberfläche belegen, daß die Shäureamidbindung gegenüber starker Hydrolyseeinwirkung stabil war.
    Notizen: In order to give the monovalent cation permselectivity to the cation exchange membrane permanently, polyethyleneimine layer was formed on the membrane surface by acid-amide bond between polyethyleneimine and the —SO2Cl groups of a styrene-divinylbenzene copolymer membrane. After the reaction, the —SO2Cl groups remaining in the inner part of the membrane were hydrolyzed by immersing the membrane into an aqueous sodium hydroxide solution.The resultant cation exchange membranes were evaluated by electrodialysis of sea water from the point of view of the monovalent cation permselectivity, electric resistance of the membrane, current efficiency, and transport number of sodium ions calculated by membrane potential in connection with reduced viscosity of the various commercial polyethyleneimines, ATR-IR measurements on the membrane surface suggested that the acid-amide bond was stable for severe hydrolysis reaction.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 2123-2133 
    ISSN: 0887-624X
    Schlagwort(e): anion exchange membranes ; photovoltage ; viologen ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Various anion exchange membranes containing the 4,4′-bipyridine moiety as anion exchange groups were prepared from membranous copolymers of chloromethylstyrene and divinylbenzene and membranes of chloromethylated polysulfone and 4,4′-bipyridine. After evaluating the electrochemical properties of the obtained anion exchange membranes, the effect of membrane species on the generation of a photovoltage was examined by irradiation using a xenon lamp. The membranes swelled with ethylene glycol were clamped between two ITO electrodes and sealed by adhesive. The generated photovoltage and photocurrent from about a 120 μm thick membrane were about 80 mV and 400 nA, respectively, in a 200K Ω load resistance, though dependent of membrane species. The voltage decreased with increasing crosslinking by the divinylbenzene in the copolymer membranes. The effect of counter ion species on the voltage was examined and a chloride ion form of membrane showed the highest photovoltage. The membranes with different thicknesses, which were prepared from polysulfone derivatives, were evaluated and the voltage decreased with decreasing thickness. Even a porous membrane from polysulfone derivatives showed a photovoltage though a porous membrane in which a methyl viologen ethylene glycol solution had been impregnated did not have a stable voltage. Also, the anion exchange membrane containing the benzyl trimethylammonium moiety, which is the conventional anion exchange groups, did not show a high and stable photovoltage upon photoirradiation. © 1996 John Wiley & Sons, Inc.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 1475-1482 
    ISSN: 0887-624X
    Schlagwort(e): anion exchange membranes ; electrodialysis ; relative transport number between two anions ; effect of hydrophobicity on anion transport ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A membranous copolymer crosslinked with divinylbenzene reacted with N,N,N′,N′-tetra-methylethylenediamine, N,N,N′,N′-tetramethyl-1,3-propanediamine, and N,N,N′,N′-tetramethyl-1,6-hexanediamine to prepare highly crosslinked anion exchange membranes. More than 80% of both tertiary amino groups of the diamines reacted with chloromethyl groups of the membrane to form crosslinkage. After formation of the high crosslinkage of the membrane was confirmed with dialysis of a neutral molecule, electrochemical properties of the obtained membranes (mainly, relative transport number between two anions in electrodialysis) were evaluated: nitrate ions to chloride ions, sulfate ions to chloride ions, fluoride ions to chloride ions, and bromide ions to chloride ions. Though larger anions, in general, were difficult to permeate through the membranes due to high crosslinkage, the number of methylene groups of the diamines (which means the increase in hydrophobicity of anion exchange groups) also affected the relative transport number between two anions. The lower the hydration of anions, the higher the relative transport number of the anions through the membranes with the hydrophobic anion exchange groups. © 1996 John Wiley & Sons, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 49-58 
    ISSN: 0887-624X
    Schlagwort(e): anion exchange membrane ; electrodialysis ; permselectivity between two anions ; pyridinium groups ; hydrophilicity of anion exchange membrane ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Anion exchange membranes with pyridinum groups and various pyridinium derivative groups were prepared from a copolymer membrane composed of chloromethylstyrene and divinylbenzene, and pyridine and pyridine derivatives. The anion exchange membranes obtained showed excellent electrochemical properties in electrodialysis. The transport numbers of sulfate ions, bromide ions, nitrate ions, and fluoride ions relative to chloride ions were evaluated in connection with the species of a substituent and the position of the substituent in the pyridinium groups. In general, when a hydrophilic substituent (methanol groups) existed at the 2-position of the pyridinium groups, nitrate ions and bromide ions, which are less hydrated, permeated through the membranes with difficulty, and sulfate ions permeated selectively through the membranes. On the other hand, when hydrophobic groups, for example, ethyl groups, existed at the 2-position of the pyridinium groups, bromide ions and nitrate ionspermeated selectively through the membranes and fluoride ions had difficulty permeating through the membranes. The carbon number of the alkyl chain of 4-alkyl pyridinium groups also affected permeation of nitrate ions and bromide ions due to the change in hydrophilicity of the membranes. Though the hydration of the anions and the species of the substituent at the 2-position of the pyridinium groups were related to selective permeation of the anion through the membranes, permeation of sulfate ions was not as sensitive to the hydrophilicity of the membranes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 49-58, 1998
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 27 (1989), S. 2229-2241 
    ISSN: 0887-6266
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: A copolymer membrane composed of 4-vinylpyridine-styrene-divinylbenezene was reacted with long chain alkyl bromides (octyl bromide, dodecyl bromide, and hexadecyl bromide) in order to introduce hydrophobic groups into the anion exchange membrane by the quaternization reaction. The resulting membranes show a marked increased in fixed ion concentration as a result of lowered water content. Although the electrical resistance of the membranes increased slightly, the apparent diffusion coefficient of hydrochloric acid through the membranes decreased markedly. Complete quaternization of the membranes by methyl iodide after reaction with the long-chain alkyl bromides caused an increase in the water content and in the apparent diffusion coefficient of the acid and a decrease in the current efficiency in electrodialysis of the acid. This is explained by the high water content of the anion exchange membranes quaternized by methyl iodide.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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