Oxidation mechanism of ferrocene with molecular oxygen

The present work is devoted to the thermodynamic and kinetic analysis of literature data on the oxidation of ferrocene in the presence of Bronsted acids, since up to now the mechanism of this reaction is still not explained     

Thermodynamics of the terpolymer of carbon monoxide,ethylene, and 1-butene

The heat capacity and the temperatures and enthalpies of physical transformations of the alternating terpolymer of carbon monoxide, ethylene, and 1-butene (the content of butene units is 10.7 mol.%) were studied by adiabatic and differential scanning calorimetry in the temperature range from 6 to 520 K. The energy of terpolymer combustion was measured at 298.15 K on an calorimeter with an isothermal shell and static bomb. The standard thermodynamic functions C°_p(T), H°(T)–H°(0), S°(T)–S°(0), and G°(T)–H°(0) for the range from Т → 0 to 400 K, the standard enthalpy of combustion, and the thermodynamic parameters of formation of the partially crystalline CO—ethylene—1-butene terpolymer at 298.15 K, as well as the thermodynamic characteristics of its synthesis in the range from T → 0 to 400 K were calculated.     

Thermodynamic properties of first- and third-generation carbosilane dendrimers with terminal phenyldioxolane groups

The heat capacities of first- and third-generation carbosilane dendrimers with terminal phenyldioxolane groups are studied as a function of temperature via vacuum and differential scanning calorimetry in the range of 6 to 520 K. Physical transformations that occur in the above temperature range are detected and their standard thermodynamic characteristics are determined and analyzed. Standard thermodynamic functions C_p^ο(T), [H°(T) ? H°(0)], [S°(T) ? S°(0)], and [G°(T) ? H°(0)] in the temperature range of T → 0 to 520 K for different physical states and the standard entropies of formation of the studied dendrimers at T = 298.15 K are calculated, based on the obtained experimental data.     

Thermodynamic properties of pyridine-containing polyphenylene dendrimers of the first-fourth generations

The temperature dependence of the heat capacity C _p° = f(T) of hard pyridine-containing polyphenylene dendrimers of the first, third, and fourth generations was studied for the first time in an adiabatic calorimeter at 6–300 K. Using the experimental data obtained, the standard thermodynamic functions, viz., heat capacity, enthalpy, entropy, and Gibbs energy in the range from T → 0 to 300 K, were calculated for these dendrimers and the value of standard entropy of formation of the studied compounds at T = 298.15 K was estimated. The low-temperature heat capacity of the dendrimers was analyzed on the basis of the Tarasov and Debye theories of heat capacity of solids and by the multifractal method. The characteristic temperatures and fractal dimensionality D were determined, and some conclusions about the type of structure topology were drawn. The isotherms of the dependence of thermodynamic functions of the dendrimers on the molecular weight were obtained.     

Thermodynamics of fluorinated derivatives of carbosilane dendrimers of high generations

The temperature dependences of the heat capacities of fluorinated derivatives of carbosilane dendrimers of high (4.5 and 7.5) generations were studied by adiabatic vacuum calorimetry in the range from 6 to 340 K for the first time. The standard thermodynamic characteristics of devitrification were estimated. The experimental results were used to calculate the standard thermodynamic functions C _p °(T), H°(T)?H°(0), S°(T)?S°(0), and G°(T)-H°(0) over the range from T??0 to 340 K and standard entropies of formation of dendrimers at T = 298.15 K. The low-temperature (T ?? 50 K) heat capacity was analyzed by using Debye??s heat capacity theory of solids and the multifractal model. The values of fractal dimensionality D were determined, and some conclusions about topology of the studied structures were made. The standard thermodynamic characteristics of the studied fluorinated derivatives of carbosilane dendrimers were compared.     

Effect of the number of iron oxide nanoparticle layers on the magnetic properties of nanocomposite LbL assemblies

Aqueous colloidal suspension of iron oxide nanoparticles has been synthesized. Z-potential of iron oxide nanoparticles stabilized by citric acid was −35±3 mV. Iron oxide nanoparticles have been characterized by the light scattering method and transmission electron microscopy. The polyelectrolyte/iron oxide nanoparticle thin films with different numbers of iron oxide nanoparticle layers have been prepared on the surface of silicon substrates via the layer-by-layer assembly technique. The physical properties and chemical composition of nanocomposite thin films have been studied by atomic force microscopy, magnetic force microscopy, magnetization measurements, Raman spectroscopy. Using the analysis of experimental data it was established, that the magnetic properties of nanocomposite films depended on the number of iron oxide nanoparticle layers, the size of iron oxide nanoparticle aggregates, the distance between aggregates, and the chemical composition of iron oxide nanoparticles embedded into the nanocomposite films. The magnetic permeability of nanocomposite coatings has been calculated. The magnetic permeability values depend on the number of iron oxide nanoparticle layers in nanocomposite film.     

Elastic plane with a physical cut loaded by an antisymmetric system of forces

The problem of determining the stress-strain state of an elastic plane with a physical cut loaded by an antisymmetric system of forces is posed and solved under the condition that the tangential stresses are homogeneous across the thickness of the layer continuing the cut.     

Interaction of polymer matrix and bound water in poly(N-vinylcaprolaktam) films

Interaction of water molecules and the polymer matrix of poly(N-vinylcaprolaktam) (PVCL), depending on temperature (?100 and 50°C) and water concentration (less than 1, 5 and 24 wt %), was investigated using the dielectric spectroscopy method (at 10^?1–10⁷ Hz). The presence of characteristic temperature points of changes of system properties, whose values depend on the quantity of water molecules in the polymer, was identified. It was found that the mechanism of temperature influence and water concentrations changes the characteristics of hydrogen bonds.