Behavior of Cross-Linked Copolymers of Acrylic Acid and 5-Vinyltetrazole in Aqueous Media

The equilibrium swelling of new hydrogels based on sodium acrylate and N,N-methylenebisacryl- amide modified with 5-vinyltetrazole in water and aqueous solutions of nickel salts in the stage of radical polymerization was studied. The influence of 5-vinyltetrazole concentration in the monomer mixture on the characteristics of the resulting copolymers was studied.     

Filled latex composites with high dielectric constant, based on dispersed ferroelectrics

The possibility of controlling the physicochemical properties of suspensions and the electrical properties of filled latex composites containing dispersed ferroelectrics was examined. The use of ferroelectrics as fillers allows preparation of polymeric composites with high dielectric constant ? and low dielectric loss, used, e.g., for the development of dielectric functional layers of electroluminescence light sources.     

Deposition of silver coatings onto sodium borosilicate glass microspheres

A technique for preparation of silver coatings on the surface of sodium borosilicate microspheres was examined. The strength and stability of the coatings were studied as influenced by pre-irradiated titanium(IV) tetrabutoxide employed as surface modifier.     

Relationship between the strengths of the composite and binder

A quantitative relationship between the strengths of a latex compound and the binder, allowing prediction of the properties of the material, has been revealed.     

X-ray Diffraction Study of Structural Changes in High-Strength Ceramics Based on Zirconium Oxide with Additions of Ytterbium and Neodymium Oxides after Hydrothermal Treatment

Crystallography Reports - A surface structural analysis of two ceramic samples of zirconium oxide (ZrO2) sintered at 1550°C, stabilized in the tetragonal form, before and after hydrothermal...     

Evolution of the calcium hydroxyapatite crystal structure under plasma deposition and subsequent reducing treatment

The structure of hydroxyapatite plasma coatings on a titanium substrate has been investigated by the X-ray Rietveld method. The hydroxyapatite crystal structure in plasma-deposited samples is characterized by strong distortions of its main element (tetrahedral PO₄ cluster) and coordination calcium polyhedra, as well as calcium deficit in the Ca2 site; however, these features do not change the main motif of the hydroxyapatite structure. The bond distortions in PO₄ clusters are estimated by the Bauer method. It is shown that hydrothermal treatment leads to the almost complete recovery of the hydroxyapatite structure.     

Synthetic boron-doped carbonado,a new electrode material: synthesis in C–metal–B growth systems aimed at the lowering of the synthesis temperature without loss of electrochemical activity

New electrode material—boron-doped synthetic carbonado (bulk polycrystalline diamond)—was synthesized at high pressures and high temperatures in the C–metal (Co, Ni, or Fe) –B growth systems. The metal borides were used as the growth medium-forming substances for graphite-to-diamond transformation at a temperature of ~?1300 °C and pressure of 8 GPa. For comparison, etalon carbonado-type electrode with nearly limiting concentration of boron in diamond was synthesized by subjecting the mixture of amorphous boron with graphite to much higher temperatures (2200–2500 °C) under the same pressure. Despite the lower content of boron in diamond synthesized in the presence of metal borides, these new boron-doped carbonado electrodes are not inferior to the etalon compact in their electrochemical activity, as judging by the onset potential of anodic chlorine evolution from KCl solution. The presence of metal-containing structural defects in boron-doped diamond matrix is supposed to be responsible for the somewhat enhanced catalytic activity of the electrodes. High-pressure synthesis of bulk metal-modified boron-doped diamond opens a new avenue in the development of superior functional electrode materials.     

Conducting polymeric composites based on butadiene-acrylonitrile latex

The possibility of controlling the physicochemical and electric properties of conducting latex composites based on butadiene-acrylonitrile latex and carbon fillers, using data on the content of active centers on the filler surface and their distribution with respect to donor-acceptor properties, was examined. To make the fillers compatible with the latexes and prevent their coagulation, the fillers were modified with Leukanol.     

Photochemical formation of silver nanoparticles in elastomer films

Photochemical deposition of silver nanoparticles in poly(butyl acrylate) and poly(butadiene-styrene) under the action of monochromatic UV light (254 nm) was studied. Changes in the polymer structure in the course of photolysis were revealed and analyzed. A mechanism of formation of silver nanoparticles was suggested. Electron microscopic examination showed that the efficiency of the particle formation is determined by the residual moisture content of the polymer films. Physicomechanical properties (tensile strength and relative elongation) of the elastomer films containing silver nanoparticles were studied.     

A study of swelling of polyurethane wastes with the aim of regeneration

The optimum time of swelling (required for weakening of the intermolecular interaction) of polyurethanes of various compositions in a series of organic plasticizers was determined. The deterioration of the physicomechanical characteristics with plasticization allows a decrease in the expenses for secondary recovery of wastes formed in polyurethane production.