The effect of silver ions electrolytically introduced into colloidal nanodiamond solution on its viscosity and thermal conductivity

Experimental data have been presented on the influence of silver on the viscosity and thermal conductivity of a dispersion of diamond nanoparticles. A stable dispersion (5 wt %) of detonation nanodiamond particles has been used in the experiments. Silver ions have been introduced electrolytically into the dispersion of diamond nanoparticles. Silver concentration was not higher than 0.05 wt %. It has been shown that the introduction of silver ions significantly affects the thermal conductivity and viscosity of the dispersion.     

Transfer coefficients of cations and anions upon glow discharge-induced nonequilibrium vaporization of solutions of alkaline earth metal salts

Firing of atmospheric-pressure, electrolytic-cathode glow discharge leads to an effect that is similar to well-known cathode sputtering. This process can be called nonequilibrium vaporization of the solution. Unlike quasi-equilibrium vaporization, the nonequilibrium process entails the transfer of nonvolatile components of the solution to the gas phase. Previously, studying glow discharge with calcium and barium chloride solutions as the cathode, we have shown that the transfer of cations and anions via the nonequilibrium vaporization of the nonvolatile solutes is not necessarily stoichiometric [1].     

Generation of a Hetero Spin Complex from Iron(II) Iodide with Redox Active Acenaphthene-1,2-Diimine

The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)Fe^III₂] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH₂Cl₂ solution was monitored by EPR spectroscopy.     

Heat-Induced Reactions of 6-Bromo-, 6-Chloro-, and 6-(Methylsulfanyl)octafl uoroindane-5-thiols with Tetrafluoroethylene. Synthesis of Dodecafluoro-2 H ,3 H ,5 H ,6 H ,7 H -indeno[5,6- b ]thiophene

Dodecafluoro-2H,3H,5H,6H,7H-indeno[5,6-b]thiophene has been synthesized as the major product of co-pyrolysis of 6-bromo-, 6-chlorooctafluoroindane-5-thiols, or bis(6-bromo-5-perfluoroindanyl)disulfane with tetrafluoroethylene under flow conditions at 400-625ºC, along with small amount of tetradecafluoro-1,2,3,5,6,7-hexahydro-s-indacene. Dodecafluoro-2H,3H,5H,6H,7H-indeno[5,6-b]thiophene formed in the reaction of 6-(meth-ylsulfanyl)octafluoroindane-5-thiol with tetrafluoroethylene at 420ºC has been isolated, and its structure has been confirmed by X-ray diffraction analysis. The schemes of the products formation involving intermediate radicals have been proposed.     

Fibroporous polytetrafluoroethylene modified with iron nanoparticles: Structure and electronic and magnetic properties

A method for synthesizing iron-containing nanocomposite based on fibroporous polytetrafluoroethylene (PTFE) is described. Fibroporous PTFE obtained under the radiation of a CO₂ laser on block PTFE is modified in supercritical carbon dioxide (sc CO₂) to form micro- and nanoporous structures. Porous fluoropolymer is treated with a solution of bis(toluene)iron(0) obtained by metal-vapor synthesis (MVS). The composition and structure of iron-containing fluoropolymer is studied by transmission electron microscopy and X-ray photoelectron and Mössbauer spectroscopy. Fe nanoparticles with an average size of 9 nm, consisting of ～30% FeO and ～70% Fe³⁺, are registered in the sample. Fe⁰ nanoparticles are stabilized in fluoropolymer pores and are coated with nanoparticles of nonstoichiometric iron oxides that have superparamagnetic properties.     

Estimating Depth of Discharge of Lithium-Thionyl Chloride Batteries from Their Impedance Characteristics

The depth of discharge of lithium-thionyl chloride batteries is estimated from their impedance characteristics. It is shown that, in principle, it can be determined when using as an informative parameter indicating the phase value at the extreme point in impedance spectra of lithium batteries.     

Effect of venous wall immobilization on the thermal degradation of collagen

The results from a comparative study of the thermal denaturation of collagen in the venous walls of reference samples and samples with varicose disease are presented. Changes in the organization of collagen network of the tissue matrix are detected via thermal analysis and multiphoton microscopy with recording of the second harmonic generation (SHG). It is established that the collagen network of venous walls degrades in varicose disease. It is shown that the disordering of the tertiary structure of collagen molecules is reflected in a 40% drop in the enthalpy of protein denaturation compared to reference (ΔH _D = 12.4 ± 4.9 J/g dry residue). The disorganization of fiber structures is recorded on SHG images. It is shown that upon the hydrothermal heating of sequestered samples of venous walls, the complete degradation of the tissue network occurs at 75°C. However, it is noted that upon the mechanical immobilization of samples of both types, the stability of collagen increases and complete denaturation is observed at temperatures above 84°C. It is suggested that the number of available conformations of polypeptide chains in the random coil state falls under tension, lowering ΔS _D and raising the temperature of the denaturation of protein.     

Correction to: The effect of small silver inclusions on the palladium activity in formicacid oxidation reaction and corrosion stability

A PdAg deposit containing ~ 25 at.% Ag is obtained by the electrochemical codeposition from an aqueous solution of Pd and Ag sulfates (Au support, 0.5 M H₂SO₄). The deposit is characterized by means of various physical, physicochemical, and electrochemical methods. The PdAg deposit demonstrates the ~ 2 times higher specific activity (per the electrochemically active surface area (EASA) of Pd) in the formic acid oxidation reaction (FAOR) as compared with the individual Pd deposit prepared under the same conditions. The effect of silver additions on the palladium activity depends on many factors. The corrosion stability of PdAg is studied in 0.5 M H₂SO₄ solution based on the overall cyclic voltammograms (CVAs) and also on anodic and cathodic half-cycles in the region E = 0.3 − 1.25 V (vs. reversible hydrogen electrode (RHE)). The electrochemical estimates are compared with the results of direct analytical determination of dissolution products in solution after anodic polarization of deposits. The total amounts of Pd dissolved substantially increase with incorporation of Ag, which is associated, first of all, with the considerable increase in the EASA; at the same time, the specific dissolution of Pd also substantially increases. The possible factors determining the active dissolution of PdAg deposits are discussed; in particular, the specific mechanism of their dissolution via silver adatoms is proposed.