Fourier transform infrared spectroscopic study of the photocatalytic degradation of cancerous cells on titanium dioxide

The method of attenuated total internal reflection Fourier transform IR spectroscopy has been used to study the oxidation kinetics of the biomolecular components of the eukaryotic cancerous HeLa cells initiated by the photogenerated charges on TiO₂. It was shown that the organic material of the cells on the porous film of the TiO₂ nanoparticles was mineralized in a such way that the TiO₂ surface was purified. The basic organic groups of Amide-I, Amide-II and phosphate were oxidized at different rates. Amide-II oxidized most rapidly, then followed Amide-I. The phosphate was the most resistant to oxidation.     

Mathematical simulation of anodic intercalation of graphite in dilute nitric acid

The article suggests a mathematical model for the process of anodic intercalation of the dense graphite suspension in dilute nitric acid, where the spontaneous intercalation is absent. The model is based on the idea of electric neutrality of a graphite particle, due to which the anion current NO₃⁻ entering the particle is precisely equal to the quantity of electrons, which are diverted from a particle to a current lead according to the mechanism of electronic conductivity provided by the outer constriction of the suspension. The anodic polarization is conditioned by the mass transfer of anions NO₃⁻ inside the equipotential graphite particle. The computational solution of the problem showed that even at a small suspension layer height (2 cm), there is a significant nonuniformity of intercalation, which corresponds to the data provided in the literature. A method for the estimation of an intercalation nonuniformity and a method for its reduction by using a multistep process were suggested. The results of the computation can be used for an estimation of the technical characteristics of the final product.     

Terbium extraction in the presence of polyfunctional organic compounds and the composition of the extract pyrolysis products

Terbium extraction with benzene solutions of acetylacetone, bipyridine, and diphenylguanidine and their mixtures from aqueous chloride solutions, in particular, in the presence of tris(hydroxymethyl)aminomethane was studied. On the basis of terbium distribution in extraction systems in combination with IR and luminescence spectroscopy data for the extracts, the complexation of terbium with these ligands was discussed. The composition of the products of the pyrolysis of extracts was studied. It was shown that pyrolysis of saturated extracts can give nano-sized bulk samples and films on a quartz substrate for both terbium oxide and terbium and manganese mixed oxides.     

Synthesis,stability in solutions,and spectral and thermal properties of alkyl-substituted 3,3′-bis(dipyrromethene) hydrobromides

3,3′-Bis(dipyrromethene) dihydrobromides (H₂L · 2HBr) with various types of alkylation have been synthesized. On the basis of IR, ¹H NMR, and electronic absorption spectra, spectrophotometric titration, and thermogravimetry, conclusions have been drawn about the influence of structural factors on the optical and thermal properties and salt stability in solutions. An increase in the degree of alkylation causes a significant high-frequency shift of the N-H stretching vibration band in the IR spectra, an upfield shift of the ¹H NMR signals of NH protons, a decrease in the auxochromic effects of protons on the aromatic system of the chromophore, and an increase in the salt stability in solutions in the presence of nucleophilic reagents and in the thermal stability in air and argon.     

Synthesis of nanosized titanium dioxide from tetrabutoxytitanium

Mesoporous TiO₂ has been obtained by template synthesis. The introduction of a surfactant in the hydrolysis of tetrabutoxytitanium in aqueous ethanol allows the structure of the resulting material to be controlled. The amorphous TiO₂ resulting from hydrolysis turns into anatase on being calcined at 300°C. As determined by X-ray diffraction, the anatase crystallite size is 70 nm in the presence of the highest surfactant concentration examined and 210 nm in the absence of a surfactant. Amorphous materials have been characterized by electron microscopy and differential thermal analysis. The ultimate benzene adsorption value has been determined for calcined mesoporous TiO₂.     

Solvation microdynamics of the Gd(3+) ion in 4-methyl-<Emphasis Type=Italic>N</Emphasis>-butylpyridinium tetrafluoroborate as probed by <Superscript>19</Superscript>F NMR and EPR

The solvation dynamics of the Gd(3+) ion in the ionic liquid 4-methyl-N-butylpyridinium tetrafluoroborate was studied by ¹⁹F NMR and EPR.     

High-frequency permittivity of nitriles of the series CH3(CH2)nCN

The propionitrile polarization characteristics at 20°C were calculated. The deformation molar polarization and permittivity of nitriles CH₃(CH₂) _n CN (n = 0, 1, 2, …) were determined.     

Laws of sorption of some aromatic heterocycles from solutions on nanoporous supercrosslinked polystyrene

Principles of the sorption of 5-tetrazole, 1,3,4-oxadiazole, and 1,2,4,5-tetrazine derivatives from solutions of various composition on nanoporous supercrosslinked polystyrene were studied by high performance liquid chromatography. The influence of the nature of heteroatom on the sorption of these heterocycles was demonstrated. The role of different types of intermolecular interactions in the sorption of the studied substances from solutions on nanoporous supercrosslinked polystyrene in quasi-normal phase and reverse phase liquid chromatography are discussed.     

A calorimetric unit for measurements of the thermal effects of reactions in solution

A calorimetric unit for measurements of the thermal effects of reactions in solution was created. The unit was designed following the classic scheme of a hermetic liquid calorimeter working under isoperibolic conditions, it had a thermometric sensitivity of 10⁻⁴ K and a calorimetric sensitivity of 10⁻² J. The accuracy of calorimeter operation was checked against the heats of solution of potassium chloride. The molar integral enthalpies of solution of glycine in water at 298 K were determined.