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  • Author or Editor: W. Zięba x
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Summary

The lipophilicity R M0 and log P TLC of thirteen novel, potentially biologically active, 12H-quino[3,4-b][1,4]benzothiazinium salts have been determined by reversed-phase thin-layer chromatography using RP-18 silica plates and methanol-aqueous Tris buffer solution mixtures as mobile phases. R M values of the compounds were linearly dependent on methanol concentration; extrapolation of these to 0% methanol gave the lipophilicity R M0. log P TLC was obtained from R M0 by use of a calibration curve obtained for five standards of known experimental lipophilicity (log P). Lipophilicity log P calcd for the thirteen quinobenzothiazines was calculated by use of nine software products. The values determined were discussed in terms of structure-lipophilicity relationships. The results indicate that chromatographic lipophilicity R M0 can be used as a measure of the lipophilicity of the azaphenothiazine derivatives investigated.

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Journal of Thermal Analysis and Calorimetry
Authors: V. Sydorchuk, W. Janusz, S. Khalameida, E. Skwarek, J. Skubiszewska-Zięba, R. Leboda and V. Zazhigalov

Abstract

Deposited zirconium phosphate samples on the base of silica and titania have been prepared using the sol–gel and mechanochemical methods. Porous structure, phase composition, and electrokinetic parameters have been studied by means of nitrogen adsorption–desorption, XRD, DTA-TG, FTIR, electrophoresis, and potentiometric titration. The compositions possess varied parameters of porous structure, structure of deposited phase, and electrokinetic properties depending on support nature and synthesis conditions.

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Abstract  

Thermal analysis was used to study thermal behavior of the sulfonated ion exchange resin Duolite C20 in the hydrogen, sodium and calcium forms. The aim of this paper was to prepare spherical carbon adsorbents. SEM and AFM microscopic methods have been applied to describe their surface characteristics. It was stated that structural parameters of prepared active carbons depend on the kind of cation present in the resin. The use of calcium form of Duolite C20 as the initial polymer precursor allowed to obtain the active carbon with better yield and better developed pore structure compared with other forms of this ion exchanger.

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Journal of Thermal Analysis and Calorimetry
Authors: E. Skwarek, S. Khalameida, W. Janusz, V. Sydorchuk, N. Konovalova, V. Zazhigalov, J. Skubiszewska-Zięba and R. Leboda

Abstract

Mechanochemical activation of individual V2O5, MoO3 and mixed vanadium-molybdenum oxide system in various media (air, water, and ethanol) has been studied. Powder X-ray diffraction, nitrogen adsorption–desorption, thermogravimetric and chemical analysis, FTIR and Raman spectroscopy, and scanning electron microscopy have been used for research of prepared milled samples. The electrokinetic properties (dependence zeta potential—pH, position of isoelectric point) of individual V2O5, MoO3 and mixed vanadium–molybdenum oxide system, synthesized via mechanochemical treatment in various medium, in aqueous solutions of electrolytes also have been determined. Initial, milled, and spent samples are characterized with the help of XRD, FTIR and Raman spectroscopy, and SEM and adsorption of nitrogen. The catalytic properties of vanadium–molybdenum oxide composition activated in different media have been investigated in reaction of oxidation dehydrogenation of propane.

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