Mutual stabilization of components in composites of polyoxomolybdates of buckyball structure and water-soluble nonionic polymers

Thermal degradation of composites consisting of polyoxomolybdates of the buckyball structure (with acetate and chloroacetate ligands) and water-soluble nonionic polymers was studied. The mutual stabilizing effect of components of the systems with polyvinyl alcohol and polyvinylpyrrolidone under UV irradiation was subjected to comparative analysis. The methods of differential scanning calorimetry, mass spectrometry, and ESR spectroscopy were used.     

Copolymers based on products of base hydrolysis of tetraethoxysilane in the presence of poly-<Emphasis Type="Italic">N</Emphasis>-vinylazoles and polyvinylpyridines

The products of base hydrolysis of tetraethoxysilane in the presence of polymeric nitrogen bases poly-1-vinylpyrazole, poly-1-vinylimidazole, poly-4-vinylpyridine, and poly-2-methyl-5-vinylpyridine were isolated. The conditions of their formation, chemical composition, structural characteristics, and sorption properties with respect to noble metals (Ag, Au, Pt, and Pd) were studied. These products are highly dispersed thermally stable interpenetrating copolymers poorly soluble in water and organic solvents. Their composition and properties are governed by the kind of the polymeric nitrogen base.     

Ceramics with mayenite structure: Molecular sieve for helium gas

It was found that mayenite {ie536-1} has selective transmission of helium gas, which is associated with its unique structural features. The permeability of helium through mayenite is (16.5–17.0) × 10^?8 cm² s^?1 Pa^?1.     

Photocatalytic Activity of Titanium Dioxide Immobilized in Polyacrylamide Hydrogels with Different Degrees of Crosslinking

Russian Journal of Applied Chemistry - Composite filamentary hydrogels based on cross-linked polyacrylamide, filled with TiO2 particles, were synthesized. The degree of crosslinking of the hydrogel...     

Experimental observation of frequency tunable x‐rays generated by interaction of nonrelativistic electrons with a silicon crystal

An experimental model of a tunable source of monochromatic x‐rays was developed using nonrelativistic electrons passing through a single crystal silicon target. Theoretical predictions for x‐ray output and characteristics were confirmed experimentally. The distinctive feature of the developed source is the possibility to tune x‐ray frequency at fixed electron beam energy. In the present report, properties and potentialities of the developed source are considered. Copyright © 2007 John Wiley & Sons, Ltd.     

Migration of plasticizers from plasticized polyvinyl chloride films

The migration of plasticizers [EDOS, di(2-ethyl hexyl) o-phthalate, di-n-butyl o-phthalate] from unfilled and chalk-filled polyvinyl chloride films plasticized with individual and binary plasticizers was studied by gravimetric analysis and IR spectroscopy. The intermolecular interaction of components in model systems was studied by IR spectroscopy and isothermal calorimetry.