Highly ordered metal oxide nanopatterns prepared by template-assisted chemical solution deposition

TiO₂, Al₂O₃, and ZrO₂ patterns composed of ordered nano motifs of various morphologies (i.e. perforations (craters), rings, canyons, wires, dots, or channels) with typical lateral dimensions of less than 40 nm and thickness below 15 nm are presented. Simple chemical solution deposition (CSD) of molecular inorganic precursors and commercial block copolymers was used to create patterns on several substrate surfaces (bare, hydrophobized or gold covered silicon wafers and ITO). Self-assembly during evaporation and subsequent stabilization at 500 °C leads to the various nanostructures. Compared to other techniques for surface nano patterning, the present method has the advantage of being cheap, reproducible and easy to scale up and does not require specialized equipment. The type, dimension, and organization of these motifs were assessed by AFM, FE-SEM, spectroscopic ellipsometry, and GI-SAXS and are shown to depend on the conditions of preparation. Usage as model surfaces for modelling of wetting properties and as nanoelectrode arrays were investigated.     

New 3π‐2Spiro Ladder‐Type Phenylene Materials: Synthesis,Physicochemical Properties and Applications in OLEDs

New routes to ladder‐type phenylene materials 1 and 2 are described. The oligomers 1 and 2 , which possess a “3π‐2spiro” architecture, have been synthesized by using extended diketone derivatives 3 and 10 as key intermediates. The physicochemical properties of the new blue‐light emitter 2 were studied in detail and compared with those of the less‐extended 1 . Owing to the recent development of fluorenone derivatives and their corresponding more conjugated analogues as potential electron‐transport materials in organic light‐emitting diodes (OLEDs) and as n‐type materials for photovoltaic applications, we also report herein the thermal, optical and electrochemical behavior of the key intermediates, diketones 3 and 10 . Finally, the application of dispiro 2 as a new light‐emitting material in OLEDs is reported.     

From dispersed nanodiscs to thin films of layered organic material via reversible swelling

We show that nanodiscs stabilized with polymers order and pile up on a surface upon drying. The resulting surface films with an average thickness of one micron are made of collapsed cohesive layers with smectic long-range order. This occurs with and without plastifying stabilizing polymer and produces crevasses. The stacked discs undergo a two-to-three-dimensional crystallization while bottom layers close to the surface fuse and produce infinite bilayers. Small angle X-ray scattering experiments demonstrate that excess polymer is segregated from the crystalline stack. Water adsorption isotherms show that reversible swelling of the excess polymer does not destroy the compact stack of partially fused nanodiscs collapsed parallel to the surface. In the absence of chemical binding, the stacks of layered nanodiscs can be removed by simple washing with pure water. AFM, TEM and SEM experiments demonstrate that presence of crevasses is quenched by the presence of a plastifying polymer.     

Mössbauer emission studies of Co-Mo/Al2O3 hydrodesulfurization catalysts: Effects of reduction and sulfidation treatments

The effect of the sulfiding temperature on the catalytic and structural properties of Co-Mo/Al₂O₃ catalysts is studied by taking into account the after-effects arising from 57-Co in the alumina. The catalytic activity is shown to be correlated to both MoS₂ or CoMoS and Co₉S₈ phases.     

Hallkoeffizient,spezifischer elektrischer Widerstand und magnetische Suszeptibilität flüssiger Hg-In-und Ga-In-Legierungen

The Hall coefficient and the magnetic susceptibility of the liquid alloys Hg-In and Ga-In have been measured and compared with the free electron model. The deviation of the measured from the calculated Hall coefficient for Hg-In is discussed. The susceptibility of carriers in Hg and Hg-In deviates strongly from the Pauli-Landau-susceptibility. This behaviour can be understood by assuming a minimum of the density of states at the Fermi level of Hg. The susceptibility data accounts for the Knight-shift ofSeymour andStyles. For liquid Ga-In, the Hall-coefficient and the magnetic susceptibility agree with the free electron model.     

A molecular orbital study of the bonding in complexes of lithium with polynuclear aromatic hydrocarbons

In a preliminary investigation of the bonding between the sub-lattices of lithium and of graphite in intercalation compounds, molecular orbital calculations are performed on systems of Li atoms complexed to one or both sides of polynuclear aromatic hydrocarbons. Energy wells calculated reveal possible sites offered to the Li atoms above the aromatic plane to form complexes in both central and edge regions of the molecule. The influence of additional complexed Li atoms on the migratory tendency of a given Li atom is also investigated, and observations made on the effect of the complexed Li atoms on the C-C bonds of the hydrocarbon.