Modification of polyvinyl chloride with Na(K) salts of 1,2,4-triazole and 1,2,3-benzotriazole

Russian Journal of Applied Chemistry - The possibility of polyvinyl chloride modification by nucleophilic substitution of chlorine with sodium and potassium salts of 1,2,4-triazole and...     

Electrosurface Properties of Hydr(oxides) and Oxide Nanostructures in 1 : 1 Electrolyte Solutions: 2. Electrokinetic Characteristics of Boehmite, Goethite, and Silicon Dioxide

The electrophoretic mobility of particles of silicon dioxide, aluminum hydroxide, and iron hydroxide was measured as a function of pH in NaCl and KCl background solutions. Isoelectric points for the investigated objects were determined. Electrokinetic potentials were calculated with allowances for the particle shape and the polarization of the electrical double layer within the framework of the Overbeek–Boes–Wiersema model.     

Regularities of latex filtration through microfiltration membranes

Filtration of suspensions of emulsifier-free monodisperse polystyrene latexes with particle sizes of 0.25, 0.3, and 0.4 μm through acetylcellulose microfilters is studied as depending on the composition of liquid phases, the rate and time of filtration, and the particle-to-pore size ratios. The effect of particle-membrane interactions, which are governed by the electrostatic repulsion and molecular attraction forces, on particle rejection by membranes is considered. It is shown that, when analyzing the mechanism for the rejection, it is necessary to take into account the electrophoretic motion of particles in the field of the streaming potential arising in the course of suspension filtration.     

Silver recovery with complexing sorbents based on 1-vinyl-1,2,4-triazole

The sorption activity of copolymers based on 1-vinyl-1,2,4-triazole toward silver ions was studied in relation to the copolymer structure and to the kind and concentration of acids. The copolymers were prepared by radical copolymerization of 1-vinyl-1,2,4-triazole with 1,1,3-trihydrotetrafluoropropyl methacrylate and divinylbenzene, with 1,1,3-trihydrotetrafluoropropyl methacrylate, methyl methacrylate, and N,N′-methylenebisacrylamide, with diethylene glycol divinyl ether, and with divinyl sulfide. The copolymers exhibit high sorption activity. They efficiently recover silver cations from acid solutions and behave as anion exchangers.     

Synthesis and properties of silver and gold nanocomposites in poly-1-vinyl-1,2,4-triazole matrix

Novel multifunctional hybrid nanocomposites with silver and gold nanoparticles stabilized by original polymer matrix based on poly-1-vinyl-1,2,4-triazole were synthesized and studied using UV and IR spectroscopy, X-ray diffraction analysis and transmission electron microscopy. The obtained nanocomposites comprise silver or gold nanoparticles of spherical and elliptical shape with size 3–20 nm and 1–10 nm, respectively.     

Phase formation in the systems Rb2MoO4-BaMoO4-R2(MoO4)3, R = Nd,Sm, Eu,Gd

Phase formation in the subsolidus area of the systems Rb₂MoO₄-BaMoO₄-R₂(MoO₄)₃ was studied by the methods of X-ray and differential-thermal analysis. In these systems ternary molybdates RbBaR(MoO₄)₃ crystallizing in the monoclinic crystal system (space group P2_1/n ) are formed. Their crystallographic parameters were calculated, and temperature dependences of the electrical conduction, dielectric permeability, and dielectric loss tangent were studied.     

Structural and electrokinetic characteristics of track-etched initial membranes and membranes modified with perfluorinated sulfocationic ionomer

Structural and electrokinetic characteristics of track-etched microfilters with pore radii of 1 μm and microfilters modified with perfluorinated sulfocationic ionomer are studied as functions of pH and concentration of KCl solutions. Colloidochemical properties of modified microfilters and perfluorinated sulfocationic MF-4SK membrane are compared.     

Regularities of the Two-Layer Adsorption of Anionic Surfactant and Cationic Polyelectrolyte on the Fused Quartz Surface

The adsorption of sodium dodecyl sulfate (SDS) on the quartz capillary surface that was preliminarily covered with a layer of cationic polyelectrolyte (CPE) is studied. The charge sign change of the modified quartz surface and subsequent increase of negative surface charge observed upon the adsorption of SDS indicate the formation of the second adsorption layer composed of surfactant molecules. It is shown that the surfactant layer is stronger attached to the surface at a higher charge of the CPE adsorption layer. Upon the formation of the surfactant layer on a looser CPE adsorption layer, the desorption of SDS molecules decreases, which can be associated with the partial penetration of these molecules into the CPE layer.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 4, 2005, pp. 573–574.Original Russian Text Copyright © 2005 by Sergeeva, Ermakova, Anuchkina, Sobolev, Churaev.