Formation of Flocs and Sediments in the Presence of Cationic Polyelectrolytes

Regularities of the flocculation of kaolin suspension with cationic polyelectrolytes based on 1,2-dimethyl-5-vinylpyridinium methyl sulfate were studied by turbidimetry, optical microscopy, and sedimentation methods. It was found that poly(1,2-dimethyl-5-vinylpyridinium methyl sulfate)-co-N-vinylpirrolidone promotes the formation of dense flocs and provide a complete sedimentation of the kaolin suspension at a high rate. The effect of dense floc formation is likely caused by a copolymer hydrophobicity and a compression of adsorbed macrocoils accompanied by squeezing of a dispersion medium out of interparticle space.     

Rheological properties of associates of ionic monomers with micelles of oppositely charged surfactants

Rheological properties of associates formed by interaction of trimethyl[methacryl-oxyethyl]ammonium methyl sulfate with sodium octyl- and dodecyl sulfate micelles, as well as associates of sodium 4-styrenesulfonate with dodecyltrimethylammonium bromide micelles in aqueous solutions were studied by steady shear and oscillatory (dynamic) shear measurements with Fourier transform. It was shown that viscosity depends on the composition and achieves maximum value at equimolar ratio of components for two of studied systems. The extremal dependence of the viscosity vs. composition is not observed for systems with sodium octyl sulfate due to weak interactions between the components. The systems exhibiting the anomalous dependencies of concentration to viscosity are viscoelastic fluids due to the physical entanglements between the associates.     

Aminolysis of 6-[1-(2,6-difluorophenyl)cyclopropyl]-5-methyl-2-(nitroamino)pyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one

The aminolysis of 6-[1-(2,6-difluorophenyl)cyclopropyl]-5-methyl-2-(nitroamino)pyrimidin-4(3H)-one with various amines in butan-1-ol and under solvent-free conditions is successful when the amino group in the reagent is sterically unshielded and the reaction medium is characterized by a high dielectric permittivity. Reactions of the title compound with sterically shielded amines are accompanied by alcoholysis where the amine acts as a base catalyst.     

Autoionization states of the beryllium atom

Using the modified Feshbach method, the^1,3S^e,^1,3P^o,^1,3D^e,^1,3S^o autoionization states of the beryllium atoms are calculated in the region of the first ionization threshold. The energies and widths of the autoionization states of Be are obtained. The results obtained are compared with experimental data and the results of existing theoretical calculations. The good agreement between the results obtained and the experimental data and other theoretical calculations is pointed out.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 23–28, March, 1984.     

Surfactant micelles as a possible template for radical polymerization: evaluation using ESR spectroscopy

Russian Chemical Bulletin - The results of studying the interaction of iogenic surfactant micelles with oppositely charged monomers using spin probe ESR spectroscopy were generalized to assess a...     

Homolytic Decomposition of Sulfonyl Chlorides

The products, kinetic parameters, and activation entropy of thermal decomposition of sulfonyl chloride groups in chlorosulfonated polyethylene (CSPE) have been studied for the first time, and it has been demonstrated that the decomposition mechanism involves simultaneous cleavage of two bonds (carbon–sulfur and sulfur–chlorine) to give an SO₂ molecule and two free radicals, which can be useful in the process of polymer structuring. The radical mechanism has been confirmed by the formation of 2,3-diphenyl-2,3- dimethylbutane on heating CSPE in isopropylbenzene. The simultaneous cleavage of two bonds is supported by the low activation energy and pre-exponential factor in the Arrhenius equation, as well as by negative activation entropy values.     

Reaction of singlet difluorocarbene with 6-methylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one derivatives

Regularities of regioselective O-difluoromethylation of 6-methylpyrimidin-4(3H)-one derivatives with difluorocarbene generated in situ were studied.     

Potential synthetic adaptogens 1. Synthesis and studies of new N-[(adamantan-1-yl)methyl]aniline derivatives based on adamantane-1-carbaldehyde

Russian Chemical Bulletin - A number of new N-[(adamantan-1-yl)methyl]aniline derivatives, which can be considered as conformationally labile analogues of synthetic adaptogen Bromantan, were...     

Regularities of flocculation of aqueous kaolinite dispersions with binary compositions of cationic polyelectrolytes

The regularities of the flocculation of kaolin suspensions with binary mixtures of cationic polyelectrolytes are studied. The relationship between the viscosity of flocculant solutions and the conditions of efficient flocculation is studied. It is established that an increase in the sedimentation rate upon the application of binary mixtures of flocculants results form their synergistic effect. The synergistic effect is assumed to be due to a reduction in the swelling coefficient of adsorbed polyelectrolyte macromolecules, which gives rise to the formation of floccules with enhanced density and strength.     

Purification of fat-containing wastewater with a complex based on poly-<Emphasis Type="Italic">N,N,N,N</Emphasis>-trimethyl[methacryloyloxyethyl]ammonium methyl sulfate and sodium dodecyl sulfate

Possibility of using complexes based on poly-N,N,N,N-trimethyl[methacryloyloxyethyl]ammonium methyl sulfate and sodium dodecyl sulfate for purification of fat-containing wastewater was examined.