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DeLongchamp DM Vogt BD Brooks CM Kano K Obrzut J Richter CA Kirillov OA Lin EK 《Langmuir : the ACS journal of surfaces and colloids》2005,21(24):11480-11483
Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films exhibit a complex structure of interconnected conductive PEDOT domains in an insulating PSS matrix that controls their electrical properties. This structure is modified by a water rinse, which removes PSS with negligible PEDOT loss. Upon PSS removal, film thickness is reduced by 35%, conductivity is increased by 50%, and a prominent dielectric relaxation is eliminated. These results suggest that the removed PSS is not associated with PEDOT and that the conductive domain network is not substantially altered by the removal of a significant fraction of insulator. The removal of PSS may benefit organic light emitting diode fabrication by reducing acid attack on indium tin oxide electrodes and lead to more robust performance in switching circuits by extending the working frequency range. 相似文献
984.
Electron-phonon coupling in oligo(para-phenylene)s is addressed in terms of the off-resonance Raman intensities of two distinct modes at 1220 and 1280 cm(-1). On the basis of Albrecht's theory, vibrational coupling and Raman intensities are calculated from first-principles quantum-chemical methods. A few-state model is used to evaluate the dependence of the mode intensities on oligomer length, planarity, and excitation wavelength. The link between electron delocalizationconjugation and Raman intensities is highlighted. Extending on prior studies, the present work focuses on providing an in-depth understanding of the origin of this correlation in addition to reproducing experimental findings. The model applied here allows us to interpret the results on a microscopic, quantum-mechanical basis and to relate the observed trends to the molecular orbital structure and nature of the excited states in this class of materials. We find quantitative agreement between the results of the calculations and those of measurements performed on oligo(para-phenylene)s of various chain lengths in the solid state and in solution. 相似文献
985.
Abbel R Frey H Schollmeyer D Kilbinger AF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(7):2170-2176
A new synthetic route is described that allows the reversible conversion of the inherently insoluble oligo-p-benzamides into soluble materials through the formation of imidoyl chlorides. Syntheses of the corresponding dimer, trimer, and tetramer are reported; these compounds can easily be purified by crystallization and are accessible on the multigram scale. Structural proof was obtained by single-crystal X-ray structures of the trimer and tetramer precursors. They can be selectively functionalized into amides or esters at the terminal carboxylic acid group followed by hydrolysis of the imidoyl chlorides to the parent amides. This new class of compounds gives access to strongly aggregating rigid rodlike materials in few synthetic steps, as is demonstrated by the preparation of poly(ethylene glycol)-co-oligo(p-benzamide) rod-coil block copolymers. 相似文献
986.
Wolfgang Richter 《Accreditation and quality assurance》2005,10(6):267-268
Editorial
ACQUAL entering its 10th year 相似文献987.
Cadisch G Espana M Causey R Richter M Shaw E Morgan JA Rahn C Bending GD 《Rapid communications in mass spectrometry : RCM》2005,19(11):1424-1428
Stable-isotope DNA probing is a culture-independent technique that may provide a link between function and phylogeny of active microorganisms. The technique has been used in association with 13C substrates while here we evaluate feasibility and limitations of 15N-DNA stable-isotope probing (SIP) using labelled and unlabelled pure microbial cultures or soil extracts. Our results showed that (15)N-DNA probing is feasible for cultures as well as soil samples. Limitations of 15N-DNA-SIP are (a) the need for relatively large quantities of DNA to visualise bands (although molecular resolution is much higher) and (b) 15N-DNA enrichment needed to ideally be >50 at%; however, this requirement can be lowered to approx. 40 atom% 15N with pure cultures using a modified CsCl centrifugation method (140K g for 69 h). These advances in 15N-DNA-SIP methodology open new opportunities to trace active microbial populations utilising specific N substrates in situ. 相似文献
988.
Benvegnu T Réthoré G Brard M Richter W Plusquellec D 《Chemical communications (Cambridge, England)》2005,(44):5536-5538
The in vitro stability of archaeosomes made from novel synthetic membrane-spanning tetraether lipids was evaluated in conditions mimicking those of oral route application in terms of bile salts, serum and low pH.. 相似文献
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