Copolymerization of Butadiene with Ethylene in the Presence of Ni-containing Organometallic Catalytic Systems and Different Modifiers

Copolymerization of ethylene with butadiene was carried out in the presence of nickel diethyldithiocarbamate and various modifiers. Triphenylphosphines were selected as modifiers. Solutions of nickel diethyldithiocarbamates and said modifiers in aromatic solvents of various concentrations have been prepared. Their physicochemical parameters, particle sizes in solutions, as well as mutual solubility were determined. It was demonstrated that these complexes are readily soluble in aromatic solvents, and the particle size in solution is in the nanometer range. These complexes were tested in the processes of copolymerization of ethylene with butadiene in combination with various cocatalysts - (tri-, diethylaluminum chloride). The products synthesized in their presence were analyzed by various physicochemical methods and their structure was confirmed. It has been shown that oligomeric and copolymer products with the required structure can be in fact synthesized in the presence of these catalytic systems. The activity and selectivity of catalytic systems have been comparatively tested in liquid phase (co) polymerization processes. The composition and conditions have been found to have a significant effect on the activity and structure of the resulting products.

Geometry of Structures Developed by Anisotropic Etching in the Nanometer Range

Geometric disadvantages of nanostructure surface developed by anisotropic etching of silicon are discussed. These disadvantages increase uncertainness of its sizes and impeded its using as an etalons for linear measurements. The greatest uncertainness are observed for structures with trapezoid profile. They make up due to defects on sidewalls of etched structures. The surface of a sidewall is proposed to be disposed in the [111] plane and so be absolutely flat. Really parts of a sidewall surface are deflected in stepwise way from the plane [111]. This phenomenon leads to deflection of angles between converging flat sections of etched structure from its known values for silicon. Consequence of this is most drastic to a measure MShps-2K due to its structure, technology of anisotropic etching and absence of required control. Sources of these surface disadvantages induced by anisotropic etching are discussed. Possibilities to decrease disadvantages are evaluated.

Structural Heterogeneity of an Amorpous Nanocrystalline Alloy in the Nanometer Range

An approach to describe the structure of amorphous alloys obtained by fast quenching from a melt, based on the fluctuation theory of phase transitions, is proposed in t in such objects.

Straightforward preparation of supramolecular Janus nanorods by hydrogen bonding of end-functionalized polymers

Janus cylinders are one-dimensional colloids that have two faces with different compositions and functionalities, and are useful as building blocks for advanced functional materials. Such anisotropic objects are difficult to prepare with nanometric dimensions. Here we describe a robust and versatile strategy to form micrometer long Janus nanorods with diameters in the 10-nanometer range, by self-assembly in water of end-functionalized polymers. The Janus topology is not a result of the phase segregation of incompatible polymer arms, but is driven by the interactions between unsymmetrical and complementary hydrogen bonded stickers. Therefore, even compatible polymers can be used to form these Janus objects. In fact, any polymers should qualify, as long as they do not prevent co-assembly of the stickers. To illustrate their applicative potential, we show that these Janus nanorods can efficiently stabilize oil-in-water emulsions.

Straightforward Preparation of Supramolecular Janus Nanorods by Hydrogen Bonding of End-Functionalized Polymers

Janus cylinders are one-dimensional colloids that have two faces with different compositions and functionalities and are useful as building blocks for advanced functional materials. Such anisotropic objects are difficult to prepare with nanometric dimensions. Here we describe a robust and versatile strategy to form micrometer long Janus nanorods with diameters in the 10-nanometer range, by self-assembly in water of end-functionalized polymers. For the first time, the Janus topology is not a result of the phase segregation of incompatible polymer arms, but is driven by the interactions between unsymmetrical and complementary hydrogen bonded stickers. It is therefore independent of the actual polymers used and works even for compatible polymers. To illustrate their applicative potential, we show that these Janus nanorods can efficiently stabilize oil-in-water emulsions.

Straightforward Preparation of Supramolecular Janus Nanorods by Hydrogen Bonding of End-Functionalized Polymers

Janus cylinders are one-dimensional colloids that have two faces with different compositions and functionalities and are useful as building blocks for advanced functional materials. Such anisotropic objects are difficult to prepare with nanometric dimensions. Here we describe a robust and versatile strategy to form micrometer long Janus nanorods with diameters in the 10-nanometer range, by self-assembly in water of end-functionalized polymers. For the first time, the Janus topology is not a result of the phase segregation of incompatible polymer arms, but is driven by the interactions between unsymmetrical and complementary hydrogen bonded stickers. It is therefore independent of the actual polymers used and works even for compatible polymers. To illustrate their applicative potential, we show that these Janus nanorods can efficiently stabilize oil-in-water emulsions.

Влияние топографических дефектов на супергидрофобные свойства покрытий на основе ZnO

Results of investigation of hydrophobic properties of ZnO coating with different surface morphology are given. It was shown that for the case of ZnO samples with surface roughness in the nanometer range, the Wenzel state is realized, and for microstructured samples - the Сassie state. For a sample with multimodal surface roughness, a superhydrophobic state was achieved with an edge angle of 151 ° and an adhesion operation of 8.82 mJ/m2. It has been demonstrated that the presence of micrometer defects on the surface of superhydrophobic samples leads to instability of the Сassie state, and as the radius of water drops increases, the Сassie-Wenzel transition is realized.

Mechanical synthesis of nanocomposites consisting of carbide-steels doped with chromium and nickel

The formation of phases in nanocomposites consisting of chromium- and nickel-doped carbide-steels obtained as a result of mechanical synthesis in a ball planetary mill and subsequent annealings has been studied. It was shown that after annealings at 700—800 °C in Fe0.80Cr0.10Ni0.10)83C17 composite the structure consisting mainly of nickel-doped austenite and chromium-doped cementite was realized. The cementite grain size is in the nanometer range.