Electrical conductivity of graphite suspensions in potassium chloride solutions in direct- and alternating-current electric fields

Electrical conductivity of graphite dispersions in aqueous KCl solutions has been measured. The measurements have been performed in alternating- (1000 Hz) and direct-current electric fields. In an alternating-current electric field, at electrolyte concentrations of 0.0005–0.01 М, the conductivity increases as depending on the mass fraction of the dispersed phase. In 0.1 М solutions, a decrease in the conductivity of the suspension is followed by an increase at dispersed phase contents of higher than 15 wt %. In a direct-current electric field, the conductivity of graphite suspensions (0.001–0.01 М KCl) varies slightly and increases at dispersed phase contents of higher than 15 wt %. In 0.1 М solutions, the specific conductivity of the suspension initially decreases and, then, increases at dispersed phase concentrations above 15 wt %. The unusual electrical properties of the suspensions have been explained as being results of variations in the capacitive and active components of the conductivity of graphite dispersions in electrolytes within the framework of a topological model. Particle polarization and a relatively high capacitive component of the conductivity mainly contribute to an increase in the conductivity of the suspensions in 0.0005–0.01 М electrolytes in the alternating-current electric field. A decrease in the conductivity of suspensions in 0.1 М electrolytes is due to a negative difference between the capacitive and active components of the specific conductivity. It has been assumed that the aggregation of graphite particles yields conducting structures at dispersed phase concentrations above 15 wt %.     

Benzenoid-quinoid tautomerism of azomethines and their structural analogs 56. Azomethine imines,derivatives of salicylic and 2-hydroxynaphthoic aldehydes

A study by IR, electronic and NMR (¹Н and ¹³С) spectroscopy together with X-ray structure analysis and quantum chemical calculations using DFT B3LYP/6-31G(d,p) determined N,N´-cyclic azomethine imines — 1-(2-hydroxyphenylmethylidene)-3-oxo-5-phenylpyrazolydin-1-ium-2-yde (1) и 1-[(2-hydroxynaphthalene-1-yl)methylidene]-3-oxo-5-phenylpyrazolydin-1-ium-2-yde (2) — to exist in solutions as isomers with an intramolecular hydrogen bond between the hydroxyl group and the nitrogen of the pyrazolidone ring. Compound 1 undergoes photoexcitation in the wavelength range 363—320 nm followed by luminescence with an anomalous Stokes shift that is caused by the intramolecular excited state proton transfer mechanism (ESIPT effect).     

Synthesis of a magnesium aluminum spinel by the burning method

Synthesis of MgAl₂O₄ from a stoichiometric mixture of aluminum and magnesium nitrates by its burning with urea, glycine, sugar, and mixtures of these as a fuel was studied.     

Sorbent based on aluminum oxide modified with Tiron

The adsorption of Tiron (disodium 4,5-dihydroxy-m-benzenedisulfonate) on aluminum oxide surface was studied, and optimum conditions for the modification of aluminum oxide surface were determined. The sorption of copper(II) on aluminum oxide modified with Tiron was studied. It was shown that the sorption of copper occurs by the mechanism of complex formation with the modifier (Tiron). The composition of the surface complex and its stability constant were determined: Cu: Tiron = 1: 1, logβ = 14.0 ± 0.4. Original Russian Text ? T.I. Tikhomirova, S.S. Kubyshev, A.V. Ivanov, P.N. Nesterenko, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7 pp. 1360–1364.     

Synthesis and physicochemical properties of organo- and water-soluble octasubstituted phthalocyanines with cyclohexylphenoxy groups

Russian Chemical Bulletin - Synthesis of 4-(4-cyclohexylphenoxy)-5-nitrophthalonitrile was developed. The method was used for the synthesis of cobalt, zinc, and copper...     

Reactions of Oxides of Some 3d Elements with Ammonium Hydrogen Difluoride

Reactions of iron, manganese(II), manganese(IV), copper, and zinc oxides with ammonium hydrogen difluoride were studied by thermogravimetry, X-ray phase analysis, IR spectrometry, and chemical analysis.     

HT-7装置电子回旋辐射系统接收天线改进

为了提高HT-7装置上等离子体电子回旋辐射(ECE)超外差诊断系统的极向分辨率,根据高斯光学原理,分析了诊断系统天线的改进方案。优化了天线的圆形角锥喇叭尺寸和凸透镜参数以及在装置上的相对位置,使天线接收到的等离子体ECE异常模二次谐波辐射的高斯光束束半径只有30mm左右,能量的高斯光学性质损失不大于13%。     

Synthesis and Spectral-Luminescent Properties of Octa-substituted Aluminum Phthalocyanines Bearing Biphenyloxy Groups

Russian Journal of General Chemistry - Mixed-substituted aluminum phthalocyanines bearing biphenyloxy substituents and nitro groups or 1-benzotriazole moieties in the periphery were synthesized on...