Diffusion-viscometric analysis and conformational characteristics of sodium polystyrenesulfonate molecules

Samples of sodium polystyrenesulfonate of molecular weights varying in a 20-fold range were synthesized. The hydrodynamic behavior of the samples was studied in a 0.2 M NaCl solution in which the initial polyelectrolyte effects are suppressed. Relationships between the molecular weight and the translational friction coefficient and intrinsic viscosity were obtained. The theory describing the hydrodynamic behavior of wormlike chains with taking into account both the percolation effects and the excluded-volume effects was applied to estimation of the length of the statistical segment and the cross section of the sodium polystyrenesulfonate molecules in 0.2 M NaCl solution.     

Synthesis and Polar and Electrooptical Properties of a Butylamine Derivative of Fullerene C<Subscript>60</Subscript>

A butylamine derivative of fullerene was prepared by the reaction of butylamine with fullerene C₆₀. The experimental electrooptical and dipole characteristics of the derivative were compared with the corresponding calculated PM3 data. The reaction product proved to be inhomogeneous in the number of the amine molecules added; it contains polar multiadducts of C₆₀ with noncentrosymmetric distribution of covalently bound amino groups over the fullerene core.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 795–802.Original Russian Text Copyright © 2005 by Evlampieva, Yakimanskii, Dobrodumov, Nazarova, Pashkov, Panarin, Ryumtsev.     

Properties of the methyl cellulose-polyvinylpyrrolidone binary system in solution and in the solid state

Rheological properties of dilute and moderately concentrated aqueous solutions of methyl cellulose-polyvinylpyrrolidone blends, as well as the conditions of gelation in them, were studied. Films were obtained from solutions of the polymer blends, and their physicomechanical properties were examined. The range of the compositions corresponding to thermodynamic compatibility of methyl cellulose with polyvinylpyrrolidone was identified by the solvent vapor sorption method and by thermomechanical examinations of the films.     

Enzymatic polymerization of vinyl monomers

The possibility of using horse radish peroxidase as a catalyst for polymerization of monomers (vinylformamide and sodium vinylsulfonate) in the presence of hydrogen peroxide and 2,4-pentanedione in aqueous medium at room temperature was studied.     

Grafting of poly-<Emphasis Type="Italic">N</Emphasis>-methacryloylaminodeoxyglucose on poly-<Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone

A graft copolymer simulating glycoprotein was prepared by reaction of poly-N-methacryloylaminodeoxyglucose containing terminal amino group with a copolymer of N-vinylpyrrolidone and acrylic acid N-hydroxysuccinimide ester.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 8, 2004, pp. 1356–1359.Original Russian Text Copyright © 2004 by Nazarova, Pavlov, Kever, Afanaseva, Panarin.     

Source of an atmospheric-pressure plasma jet formed in air or nitrogen under barrier discharge excitation

We analyzed the atmospheric pressure plasma jet excited in air and nitrogen by a barrier discharge. The source forming stable plasma jets of length up to 4 cm in air and nitrogen is constructed, and its energy and spectral characteristics are measured.     

Emission properties of apokamp discharge at atmospheric pressure in air,argon, and helium

Emission spectra of the plasma jet of apokamp discharge in air, helium, and argon are studied. Apokamp at atmospheric pressure is formed in the areas of strengthening of the electric field near the bends in the channel of the pulse-periodic discharge and is directed perpendicularly to the discharge channel. Apokamp consists of a bright narrow “appendage” connected with the discharge channel and with the diffuse jet emerging from the channel. It is shown that, in helium, the emission of the diffuse part of apokamp is dominated by N₂ and N₂ ⁺, while emission of the “appendage” display lines and bands of He, N₂, N₂ ⁺, O, and OH. In argon, emission spectra of the diffuse part of the plasma jets contain not only N₂ and N₂ ⁺, but also Ar lines. It is assumed that the surrounding air plays an important role in the formation of the diffuse part of apokamp in helium and argon.     

Relaxation properties and complex formation of copolymers of 2-deoxy-2-methacrylamido-D-glucose and unsaturated acids

With the use of polarized luminescence, relaxation times characterizing the intramolecular mobility of luminescent labeled copolymers of 2-deoxy-2-methacrylamido-D-glucose and unsaturated acids in solutions are determined in both nonionized and ionized states. Elements of the secondary structure typical for poly(methacrylic acid) are formed in copolymers with a high content of methacrylic acid (≥50 mol %) in their nonionized state. This structure is destroyed during ionization. Equilibrium stability constants for complexes of the copolymers with cationic surfactants are determined. Quantitative characteristics of the effects of the surfactant and copolymer structures and the ionic strength of solution on complex formation are estimated.