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561.
Sefik Suzer Ozgur Birer Adnan U. Sevil Olgun Guven 《Monatshefte für Chemie / Chemical Monthly》2001,100(3):185-192
2-Chloro-polyaniline (2-Cl-PANI) in its non-conducting (emeraldine base, EB) form, prepared by a chemical route, was dissolved together with poly-(vinylchloride) (PVC) in THF for casting into thin (10–50 μm) films. Upon exposure to UV radiation, the electrical conductivity of these films increased by more than 4 orders of magnitude (from 10−6 to 10−2S/cm). This is attributed to the dehydrochlorination of PVC by exposure to energetic photons and subsequent doping of 2-Cl-PANI (i.e. conversion to emeraldine salt, ES) by in situ created HCl. The doped films could be returned to their undoped form by exposure to NH3 vapours. The UV-induced doping/NH3 undoping cycles could be repeated several times. Various spectroscopic techniques were employed to follow the changes in the films upon exposure to UV radiation. The same photo-dehydrochlorination process has also been utilized for optical and/or lithographic purposes by preparing PVC blends containing methyl violet, and acid-base indicator dye. The photo-dehydrochlorination can be effectively sensitized by incorporating hydroquinone into the PVC blends containing methyl violet. 相似文献
562.
563.
Alejandro Adem 《Inventiones Mathematicae》1993,114(1):489-514
564.
The ion dip spectra toluene and aniline were measured using a supersonic free jet. It was demonstrated that an ion dip spectrum gives a ratio of the transition probablity from a ground state to a resonant intermediate state and that from the intermediate state to the ionization continuum. 相似文献
565.
S0–S0 absorption spectra of phenol dimer and toluene-cyanobenzene complex in a supersonic free jet have been observed by the use of the multiphoton ionization technique. Two low-frequency vibrations at 15 and 112 cm-1 appear in the spectrum of phenol dimer, which were assigned as the bending and stretching mode of hydrogen bonding, respectively. Toluene—cyanobenzene complex also exhibits a low-frequency vibrational progression which indicates the dissociation of the complex in the S1 state. 相似文献
566.
Adem Zengin Ertan Yildirim Tuncer Caykara 《Journal of polymer science. Part A, Polymer chemistry》2013,51(4):954-962
Well‐defined, high‐density poly(2‐(2‐methoxyethoxy)ethyl methacrylate) [poly(MEO2MA)] brushes were fabricated through a reliable strategy by the combination of self‐assembly of a monolayer of 3‐aminopropyltrimethoxy silane on silicon surface to immobilize 4‐cyano‐4‐(dodecylsulfanylthiocarbonyl)sulfanyl pentanoic acid chain transfer agent and reversible addition‐fragmentation chain transfer‐mediated polymerization of MEO2MA. The whole fabrication process of the poly(MEO2MA) brushes was followed by water contact angle, grazing angle‐Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and atomic force microscopy. Characterization of the poly(MEO2MA) brushes, such as molecular weight and thickness determination, were measured by gel permeation chromatography and ellipsometry, and the grafting density was estimated. The temperature‐responsive property of the poly(MEO2MA) brushes was further investigated and the result verified the brush‐to‐mushroom phase transition of the poly(MEO2MA) chains from low to high temperature. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
567.
The vacuum ultraviolet absorption spectra of various hydrogen bonded amides were measured at various temperatures and concentrations. It was found that the characteristic absorption bands of amides, which appear at 180–190 m, greatly change by hydrogen bonded dimer formation and moreover their changes are sensitive to the relative orientation of the monomers. That is to say, they shift to shorter wavelengths by about 6000 cm–1 by the hydrogen bonded ring dimer formation and shift to longer wavelengths by about 3000 cm–1 by the hydrogen bonded chain dimer formation. The theoretical consideration on the energy level splittings due to hydrogen bonded dimer formation explained satisfactorily these observations. The results seem to be important in connexion with the determination of the configurations of polymers which contain peptide bonds as a unit.
Zusammenfassung Vakuum-UV-Absorptionsspektren verschiedener Amide, die H-Brücken ausbilden, wurden vermessen. Die charakteristische Bande der Amide bei 180–190 m wird durch H-Brücken in Abhängigkeit von der Form des gebildeten Dimeren verschoben: so ist die Verschiebung im Falle der Ringbildung +6000 cm–1, im Falle linearer Verkettung –3000 cm–1. Dies Phänomen wird theoretisch erklärt. Die Ergebnisse sind für die Strukturaufklärung von polymeren Amiden von Bedeutung.
Résumé Les spectres d'absorption U.V. dans le vide ont été mesurés pour différentes amides formant des liaisons hydrogène. La bande caractéristique des amides vers 180–190 m. est déplacée lors de la formation d'une liaison hydrogène: pour des dimères ce déplacement est de +6000 cm–1 lors de la formation d'un composé cyclique et de –3000 cm–1 lors de la formation d'un composé linéaire. On explique théoriquement ce phénomène. Les résultats ont une signification pour la compréhension de la structure des amides polymères.相似文献
568.
569.
S. Nonose Y. Sone K. Kaya 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,19(4):357-359
Using two independent vaporization lasers, bimetallic clusters composed of transition elements and A1 were generated by the laser vaporization method. Reactivity toward hydrogen adsorption of bimetallic clusters was compared with genuine clusters. It was found that A1 which has no reactivity toward hydrogen plays a role of either inhibitor or accelerator of the reaction when A1 is mixed with Nb or Co. Unusual stability of Co12 V1 in contrast to the high reactivity of Co12–13 is attributed to the rigid geometric structure where V occupies the central position. 相似文献
570.
A method for speciation, preconcentration and separation of Fe2+ and Fe3+ in different matrices was developed using solvent extraction and flame atomic absorption spectrometry. PAN as complexing reagent for Fe2+ and chloroform as organic solvent were used. The complex of Fe2+-PAN was extracted into chloroform phase in the pH range of 0.75-4.0 and Fe3+ remains in water phase in the pH range 0.75-1.25. The optimum conditions for maximum recovery of Fe2+ and minimum recovery of Fe3+ were determined as pH = 1, the stirring time of 20 min, the PAN amount of 0.5 mg and chloroform volume of 8 mL. The developed method was applied to the determination of Fe2+ and Fe3+ in tea infusion, fruit juice, cola and pekmez. It is seen that there is high bioavailable iron (Fe2+) in pekmez. The developed method is sensitive, simple and need the shorter time in comparison with other similar studies. 相似文献