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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 5 (1995), S. 191-198 
    ISSN: 1057-9257
    Schlagwort(e): TiN ; adhesion ; PVD ; electron shower ; arc ion plating ; sputtering ; wear ; surface ; morphology ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Elektrotechnik, Elektronik, Nachrichtentechnik , Physik
    Notizen: It has been found that TiN films with high wear resistance and high adhesion can be prepared by electron shower deposition and arc ion plating on glass and austenitic stainless steel (SUS 316) substrates. The high wear resistance is principally explained by the grain size and surface morphology. Fine {100}-faceted crystals (10-150 nm) grew on the surface. The typical morphology of the crystals was triangular pyramidal. The crystallite size was changed by the bias voltage. Faceted crystals produced by arc ion plating were rounded and smoothed by a change in bias, but were unaltered in samples prepared by the electron shower process. The fine faceted surfaces had higher wear resistance than the granularly rounded ones. When TiO2 was formed at the interface of the glass substrate, the adhesion was lowered. The high-adhesion film prepared by electron shower deposition contained a small amount of TiO2 at the interface.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    ISSN: 0003-3146
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Es wird eine neue Methode zur Einführung von hydrophilen Polyetherseitenketten in segmentierte Polyurethane unter Verwendung eines Polypropylenoxid-Macromeren mit 1,3-Diol-Gruppen an einem Kettenende, die als Kettenverlängerer fungieren, beschrieben. In diesem Prozeß wird eine Seitenkette quantitativ und direkt in medizinische Polyurethanelastomere eingebaut. Diese Entwicklung ist auch für Biowerkstoffe in künstlichen Organen von Interesse.
    Notizen: A new method of introducing a hydrophilic polyether side chain into segmented polyurethane using a polypropylene oxide macromer with 1,3-diol at one chain-end, which behaves as chain extender, is described. In this procedure, a molecular-designed side-chain is incorporated quantitatively and directly into polyurethane biomedical elastomer. The design is also of interest to biomaterials in artificial organs.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 453-458 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The interaction between ionizable carboxyl groups and the conformation of poly-(glutamic acid) (PGA) in aqueous solution were investigated by the mechanical method. The dynamic rigidity of the PGA solution has a maximum value at the pH corresponding to about 50% neutralization point. This may be due to establishing of a maximum attractive force by proton/charge fluctuation between ionizable carboxyl groups at that pH. The dynamic viscosity has a sharp change in the region of pH 5.5-6.5. It is suggested that this behavior is due to the helix-coil transition.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 164 (1973), S. 203-213 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Um die katalytische Wirkung des Polymer-Liganden zu untersuchen, wurden Kupfer-Poly(vinylpyridin) (Cu-PVP)-Komplexe als Katalysatoren für die oxydative Polymerisation der Phenole eingesetzt. Der Katalyseverlauf wurde diskutiert.Die mit dem Cu-PVP-Komplex katalysierte Polymerisation des 2,6-Dimethylphenols verlief langsamer als die mit dem Kupfer-Pyridin-Komplex katalysierte. Aufgrund der Messung der kinetischen Konstanten wurde angenommen, daß der raumfüllende PVP-Ligand die Koordination des Monomeren zum Metall stört. Die Polymerisation des Monomerengemisches aus XOH und o-Kresol verlief in Gegenwart des Cu-PVP-Katalysators bei höheren Umsätzen mit konstanter Geschwindigkeit. Die Ausbeute und das Molekulargewicht des erhaltenen Polymeren waren größer als in den Fällen, in denen Cu-Pyridinoder Cu-γ-Pikolin-Komplexe als Katalysatorsysteme verwandt wurden. XOH wird vorzugsweise mit dem Cu-PVP-Katalysator aktiviert, da das Oxydationspotential des XOH niedriger ist; dadurch wird die Wirkung des PVP-Liganden erfaßbar.
    Notizen: In order to study the catalytic effects of the polymer-ligand, copper-poly(vinylpyridine) (Cu-PVP) complexes were used as catalyst for the oxidative polymerization of phenols. The catalysis was discussed.The rate of the 2,6-dimethylphenol (XOH) polymerization catalyzed by the Cu-PVP complex was slower than that catalyzed by a Cu-pyridine complex. By the measurement of the kinetic constants, it was suggested that a bulky PVP ligand obstructed the coordination-step of the monomer and the electron-transfer-step from the coordinated monomer to the cupric ion. The polymerization of the mixture of XOH and o-cresol with Cu-PVP as catalyst was saturated at a higher conversion, and the yield and the molecular weight of the polymer obtained were larger than in the cases where the Cu-pyridine or the Cu-γ-picoline complex systems were used as catalysts. XOH is preferentially activated by the Cu-PVP catalyst because its oxidation potential is lower, thus the effect of the PVP ligand may be observed.XOH was polymerized by the swelled Cu-PVP complex as a heterogeneous catalyst in benzene or a benzene containing mixture of solvents. The catalyst was recovered by filtration in a high yield and re-used repeatedly. Cu-PVP complexes are relatively stable toward alkali because of their chelate structure. The polymerization was accelerated 3 to 5 times in alkaline solution, and the side-reaction was suppressed.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: It was found that the manganese complex formed from toluene-3,4-dithiol and MnCl2 (Mn-TDT) and the complex formed from disodium 1,2-dicyanoethylenedithiolate (maleonitriledithiol) (Mn-MNT) show high activities as catalysts for the oxidative polymerization of 2,6-dimethylphenol. Mn-TDT is active only in the presence of an alkaline agent such as potassium hydroxide. Its activity is still higher when it is synthesized in ethanol and isolated just before use. Mn-MNT is similarly active without being isolated, and it is active even in the absence of potassium hydroxide when the mole ratio MNT/Mn is high. This is probably due to the alkaline character of MNT. Mn-TDT or Mn-MNT complex produce poly[oxy(2,6-dimethyl-1,4-phenylene)] selectively, and no formation of the diphenoquinone 2,2′,6,6′-tetramethyl-1,1′-dioxo-4,4′-bicyclohexa-2,5-dienylidene was observed.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Polynuclear dithiolato-metal-dye complexes were prepared and their photochemical behaviors were studied. The dimercapto ligands used were maleonitriledithiol (MNT) and toluene-3,4-dithiol (TDT); metal ions were copper, manganese and nickel; and dyes were thionine (TH), tolusafranine (SAF) and methylene blue (MB). From IR spectra, elemental analyses and magnetic measurements they were found to be polynuclear complexes having bis(dithiolato)-metal structure incorporating the dyes as cations. The complexes showed almost the same visible spectra as the free dyes. The molar absorption coefficients of the maximum absorption were in most cases larger than in the free dye. The dithiolato-metal complex affected remarkably the photochemical reactivity of the dye incorporated in it. The rates of the photochemical reduction of the TH complexes (Cu-MNT-TH, Mn-MNT-TH and Cu-TDT-TH) in hexamethylphosphortriamide were higher than the free TH, while those of the SAF complexes (Cu-MNT-SAF and Mn-MNT-SAF) and MB complexes (Cu-MNT-MB and Ni-MNT-MB) were much lower than the free SAF and MB, respectively.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 1111-1118 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Methylviologen (1,1′-dimethyl-4,4′-bipyridinium dichloride, MV2+) absorbed on cellulose paper can be reduced photochemically in solid phase. The ESR spectrum (singlet; g = 1,967, ΔHmsl = 13,5 gauss) shows the photochemical formation of its cation radical (MV•+). The MV•+ formed on cellulose is unusually stable against oxidation by oxygen. Photochemical formation and slow oxidation of MV•+ under air occur fairly reversibly. The concentration of MV•+ and the optical density (O.D.) at 620 nm show a linear relationship. The concentration of MV•+ at 1 O.D. corresponds to 1,07.10-8 spins/cm2 cellulose paper. The formation of carbonyl groups in MV2+/cellulose after irradiation indicates that cellulose acts as electron donor. The mechanism of the solid phase photoreduction is discussed in relation to the effect of other carbohydrates or inorganic materials as adsorbents.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: In order to prepare polysiloxanes with the ability of electron transport, pendant viologen groups were introduced. Chloromethylated poly(methyl-β-phenethylsiloxane) (2) was reacted with monoalkylbipyridinium chlorides (3a, 3b) to give polysiloxanes (4a, 4b) containing pendant viologen groups. These polymers show reversible redox behavior. They are deposited on ITO electrodes when the pendant viologen dication groups are electrochemically reduced to cation radicals. The polymer deposited shows an absorption maximum (λmax) at 500 nm, which is due to a highly aggregated structure of cation radicals. On the contrary, when the electrode was coated by the polymer before the measurement (pre-cast membrane), the cation radicals formed electrochemically show λmax at 530 nm, indicating that the degree of aggregation is lower than that in the membrane formed reductively from solution.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 192 (1991), S. 1649-1654 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The emission characteristics of the excited state of tris(2,2′-bipyridine)ruthenium(II), Ru(bpy)32+, adsorbed on a silk fibroin membrane is studied. The life time of the excited state of the adsorbed Ru(bpy)32+ is unusually longer (1 000 ns) than that of Ru(bpy)32+ in aqueous solution (598 ns). The excited state of the adsorbed Ru(bpy)32+ is quenched by oxygen when dipped in methanol, but not in water. The quenching by oxygen in methanol follows the Stern-Volmer equation. The luminescent characteristics of the adsorbed Ru complex is discussed in terms of binding in hydrophobic domains composed of tyrosine residues of the protein.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2795-2809 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Die katalytische Aktivität bei der oxidativen Polymerisation von 2,6-Dimethylphenol (8) der folgenden halbleitenden organischen polymeren Metallkomplexe wurde untersucht: polymere Komplexe, die gleichzeitig Bis(äthylen-1,2-dithiolo)Cu(II)- oder Fe(III)-Komplexe und Cu(II)-Phthalocyanin-Strukturen (3a-c) enthalten bzw. die gleichzeitig Bis(äthylen-1,2-dithiolo)Cu(II)- oder Fe(III)-Komplex- und Hemiporphyrazin-Strukturen (5a-c) aufweisen, und Koordinationskomplexe, die sich aus Dimercaptomaleinsäuremonoamid (7) aufbauen lassen. Es wurde gefunden, daß eine Suspension der unlöslichen polymeren Cu-Komplexe vom Typ 3 in Gegenwart von Sauerstoff die oxidative Polymerisation bei Raumtemperatur katalysiert und daß Poly[oxy(2,6-dimethyl-1,4-phenylen)] (9) in sehr guter Ausbeute entsteht. Polymere Komplexe vom Typ 5 waren für sich allein inaktiv. Eine wesentlich erhöhte Aktivität zeigten die polymeren Komplexe vom Typ 3 und 5 in Gegenwart von wenig Cu(II)-Pyridin-Komplex in Pyridin-Lösung. (Die zugesetzten Mengen waren so niedrig, daß Cu(II)-Pyridin allein nur eine geringe Aktivität aufweis.) Polymere Komplexe mit Bis(äthylen-1,2-dithiolo)Fe(III)-Strukturen waren auch in Anwesenheit des Cu(II)-Pyridin-Komplexes inaktiv.
    Notizen: In the oxidative polymerization of 2,6-dimethylphenol (8) the catalytic activities of the following semiconducting organic polymeric metal complexes were studied: polymeric complexes containing bis(ethylene-1,2-dithiolato)Cu(II) or Fe(III) complexes and copper(II) phthalocyanine structures (3a-c), catalysts consisting of bis(ethylene-1,2-dithiolato)-Cu(II) or Fe(III) complex structures and hemiporphyrazine type structures (5a-c), and also polymers containing a copper complex of dimercaptomaleic acid monoamide (7). It was found that a suspension of the insoluble bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of type 3 catalyzes the polymerization in the presence of oxygen in pyridine at room temperature producing poly[oxy-(2,6-dimethyl-1,4-phenylene)] (9) in very good yields. Polymeric complexes of type 5 were inactive by themselves. However, we showed that bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of both the 3 and 5 type possess great activities if they are used in the presence of small amounts of copper(II)-pyridine complex in pyridine solution (the chosen concentration was so low that the Cu(II)-pyridine complex alone had only a small activity). Bis(ethylene-1,2-dithiolato)Fe(III) complexes of both the 3 and 5 type were inactive even in the presence of the Cu(II)-pyridine complex.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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