Yu. S. Chekryshkin

Thermodynamic parameters of adsorption described by the logarithmic Temkin isotherm

Thermodynamic analysis of the adsorption Temkin isotherm was performed. The equations that describe the dependence of the thermodynamic functions on the amount adsorbed were obtained. A relationship between the excess differential and mean molar thermodynamic functions was found. The thermodynamic approach does not contradict the molecular statistical theory and appears to be more general.

Application of inorganic compounds at the thermal processing of polyvinylchloride

A review of publications on the effect of various inorganic additives (metals oxides, hydroxides, chlorides and carbonates) on the process of dehydrochlorination and pyrolysis at the thermal processing of polyvinylchloride (PVC). A decrease in temperature of the PVC dehydrochlorination step is noted at processing in the presence of chromium, iron, cobalt, copper and molybdenum oxides. Aluminum, titanium, circonium, cerium and lead oxides do not change temperature of beginning of PVC destruction. No effect noted of the oxides at the second step of PVC destruction.

Calculation of the sticking coefficient in the case of the linear adsorption isotherm

The expression of the sticking coefficient for the linear adsorption isotherm was derived. The sticking coefficient is an increasing temperature function and directly related to the entropy factor. The limits of applicability of the derived equation are discussed.

Adsorption of chlorobenzene and benzene on γ-Al2O3/atl>

Adsorption of chlorobenzene and benzene on γ-Al2O3 was investigated in the 413--572 K temperature region at an adsorbate partial pressure ranging from 2 to 1000 Pa. The adsorption isotherms were measured and the isosteric heats and the entropy characteristics of adsorption were determined. The experimentally found and theoretically calculated entropy changes upon adsorption were compared. The mobility of the molecules of both adsorbates in the adsorption layer was limited with respect to that predicted by the ideal two-dimensional gas model. The mechanism of adsorption of benzene and chlorobenzene is discussed.

Thermodynamic quantities of adsorption described by Freundlich isotherm

Thermodynamic analysis of the Freundlich adsorption isotherm was performed. Equations describing the thermodynamic characteristics of adsorption as a function of the adsorbed quantity are presented, and relationships between the excess differential and average molar thermodynamic adsorption quantities were obtained. It was shown that the thermodynamic approach does not contradict the molecular statistical theory and provides more general equations. A model of adsorption described by the Freundlich isotherm is discussed.

The oxidation of zinc and barium chlorides with oxygen to obtain chlorine and finely dispersed zinc oxide

The regular features of the reaction of calcium, barium, and zinc chlorides with oxygen to form molecular chlorine and corresponding metal oxides are studied. The rate constants of the reaction were determined. The effective activation energies of oxidation of chloride ions were calculated with due to regard for the diffusion at the gas-chloride melt interface, which is especially pronounced at a temperature above 550°C. Zinc oxide being formed was separated from the reaction mixture, and the dispersion of its particles was determined.

Synthesis and antimicrobial activity of mono-and biquaternized derivatives of dipyridylethanes and dipyridylethylenes

A series of mono-and biquaternized derivatives of dipyridylethanes and dipyridylethylenes has been synthesized and characterized with respect to antimicrobial activity. The new compounds exhibit structure-dependent antimicrobial action on both Gram-negative (E. coli) and Gram-positive (St. aureus) bacterial species. Monoquaternized dipyridylethane and dipyridylethylene derivatives show a higher antimicrobial activity than compounds with two onium nitrogen atoms; derivatives of dipyridylethane are less active than the analogous derivatives of dipyridylethylene. A high antimicrobial activity (MIC ∼ 1 mg/ml) was observed for 1-[N-cetyl-(4-pyridinium)]-2-(4-pyridyl)ethylene.

Synthesis and antimicrobial activity of new mono-and biquaternized dipyridylethanes and dipyridylethylenes

A series of mono-and biquaternized derivatives of dipyridylethane and dipyridylethylenes were synthesized in order to study their antimicrobial activity (AMA) with respect to Gram-negative (E. coli) and Gram-positive (S. aureus) species. It is established that the antimicrobial activity depends on the nature of the radical on the nitrogen atom, the positions of the ethane and ethylene bridges between the rings relative to the onium nitrogen atoms, and the presence of conjugated systems between these atoms. The maximum AMA with respect to the indicated test microbe strains was observed for 1-(N-dodecylpyridin-4-yl)-2-(4-pyridyl)ethylene bromide (MIC 3.9 and 2.0 μg/mL, respectively).

The regular features of chlorine formation in the systems NaCl-MexOy-O2 and Ca(Zn)Cl2-MexOy-O2

The reaction of sodium, calcium, and zinc chlorides with atmospheric oxygen in the presence of transition metal oxides and antimony oxide at temperatures exceeding the melting temperatures of chlorides was studied. The content of chorine, product of oxidation of chloride ions in molten NaCl and CaCl2, was determined as a function of the polarization force of cations of transition metal oxides.

Adsorption of benzene on the V2O5/γ-Al2O3 catalyst

Adsorption of benzene on the V2O5/γ-Al2O3 catalysts was studied in the temperature interval from 443 to 493 K and at partial pressures of the adsorbate ranging from 1 to 400 Pa. The adsorption isotherms were plotted. The isosteric heats and various entropy characteristics of adsorption were determined. Mobility of benzene in the adsorption layer is restricted compared to the model of ideal dimeric gas. The adsorbed amounts of benzene and chlorobenzene are compared.