Ordered and disordered pNA molecules in mesoporous MCM-41

Para-nitroaniline (pNA) has been incorporated into the one-dimensional channels of mesoporous MCM-41, the hexagonal member of the M41S family of ordered mesoporous silicate materials. The composite material shows a number of remarkable features, depending on the sorption procedure for the organic component, the after treatment, and the annealing time of the composite. In X-ray diffraction experiments different states of one-dimensional ordering of the sorbate molecules in the channel pores are observed. In agreement with the molecular dipole, chain-like coherent domains with the long axis of the sorbate molecule parallel as well as perpendicular to the host channel axis show up. In aged samples the periodic ordering of the pNA molecules is lost, and nonlinear optical properties of the composite have been measured in second harmonic generation experiments indicating the presence of a polar direction in the sampl

Aufbau der Vorlesung ''Einfuehrung in die Fachdidaktik'' fuer angehende Gymnasiallehrer im WS 1982/83 an der Universitaet Muenchen

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Magnéli phases Ti₄O₇ and Ti₈O₁₅ and their carbon nanocomposites via the thermal decomposition-precursor route

A new synthetic approach for producing nano-powders of the Magneli phases Ti4O7, Ti8O15 and their carbon nanocomposites by thermal decomposition-precursor route is proposed. The formation mechanism of the single-phase carbon nanocomposites (Ti4O7/C and Ti8O15/C) from metal-organic precursors is studied using FT-IR, elemental analysis, TG, STA-MS and others. The synthesis parameters and conditions were optimized to prepare the target oxides with the desired microstructure and physical properties. The electrical and transport properties of Ti4O7/C and Ti8O15/C are investigated. These nano-materials are n-type semiconductors with relatively low thermal conductivity in contrast to the bulk species. The nanostructured carbon nanocomposites of Magneli phases achieve a low thermal conductivity close to 1 W/m K at RT. The maximum ZT(570) (degrees C) values are 0.04 for Ti4O7/C powder nanocomposite and 0.01 for Ti8O15/C bulk nanocomposite. (C) 2015 Elsevier Inc. All rights reserved

Solarzellen mit verlängerter und ausgleichender Wirkungsdauer

Use of a photovoltaic element comprising a first region on which incident photons are subjected to a photovoltaic conversion, and a second region that is arranged such that a light radiation penetrates into the second region and passes into the first region, for producing electricity under low light or without light conditions, is claimed. The second region comprises a long-lasting luminescent material. An independent claim is also included for the photovoltaic element comprising the long lasting inorganic luminescent material embedded in a matrix with organic components. The long-lasting inorganic luminescent material is embedded in the form of nano-crystalline particles in the organic matrix, and the matrix provided with the nano-crystalline particles comprising a transmittance of at least 80 %, in a wavelength of 450 nm to at least 1100 nm

Diamond-ceramics composites - New materials for a wide range of challenging applications

Materials with enhanced wear resistance are of great interest for modern industry. The different ways of producing superhard ceramic materials are shortly reviewed. In detail, the preparation of diamond–silicon carbide composites by reactive infiltration of diamond preforms with liquid silicon at ambient pressure is investigated. In addition to homogeneous SiC/diamond materials with nearly 50 vol.% of diamond layered composites were also prepared. The microstructures of the materials prepared under different infiltration conditions were analyzed using X-ray diffraction, electron microscopy, electron back-scatter diffraction (EBSD) and Raman spectroscopy. The properties of the materials depend strongly on the formation of graphite interlayers at the boundary between SiC and diamond. Hardness of 47 GPa was reached for materials where the formation of the interlayer was prevented