A. V. Novoselova

Electrochemical behavior of ytterbium in an equimolar melt of sodium and potassium chlorides

Electrochemical reduction of Yb(III) ions to Yb(II) was studied in an equimolar NaCl-KCl melt in the temperature range 973–1075 K. Linear, cyclic, and square-wave voltammetry, chronopotentiometry, and potentiostatic electrolysis with tungsten as the working electrode were used in the study.

Preparation and investigation of polymer-polymer compositions based on polyacrylonitrile and aromatic polyamic acid

A modification of polyacrylonitrile (PAN) was carried out. As a result, a polymer compatible (in contrast to common PAN) with polyamic acid (PAA) was obtained. PAA, PAN and their mixtures in solution and in film were investigated by viscometry, massspectrometric thermal analysis (MTA), TG and electron microscopy. The physico-mechanical characteristics of the corresponding composite films were obtained.ZusammenfassungPolyacrylnitril (PAN) wurde modifiziert, das entstandene Polymer ist (im Gegensatz zu herkömmlichem PAN) ausreichend mischbar mit Polyamicsäure (PAA). PAA, PAN und ihre Gemische wurden in Lösung und als Film mittels Viskosimetrie, massenspektrometrischer Thermoanalyse (MTA), TG und Elektronenmikroskopie untersucht. Die physisch-mechanischen Charakteristika der entsprechenden Verbundstoffilme wurden ermittelt.

Cocarbonization of polyacrylonitrile with lignin

The boundary and parameters of the thermochemical reaction of lignin and polyacrylonitrile were determined by dynamic and isothermal thermal analysis. The time, temperature, and concentration effects of formation of composites, allowing preparation of new carbonizates with enhanced heat resistance and noticeably higher carbon residue, were studied.

Redox reaction Yb(III) + e = Yb(II) in a molten eutectic mixture NaCl-2CsCl

Potentiometric method was used to measure the redox potentials of Yb3+/Yb2+ in a eutectic melt of sodium and cesium chlorides relative to a chlorine reference electrode in the temperature range 823–973 K. The basic thermodynamic characteristics of the redox reaction YbCl2(s.) + 1/2Cl2(g.) ai YbCl3(s.) were calculated from the conditional standard potentials E*(Yb3+/Yb2+).

Potential activity of hydrolytic lignin in copolymerization reactions

Structural-molecular characteristics of hydrolytic lignin samples from various factories were studied and their potential activity in copolymerization with polyacrylonitrile was determined.

Electrochemical study of the redox reaction Yb(III) + e ⇄ Yb(II) in a molten LiCl-KCl eutectic

Electrochemical process of reduction of Yb(III) ions and oxidation of Yb(II) ions in a molten LiCl-KCl eutectic in the range 723–973 K was studied by linear, cyclic, and square-wave voltammetry and zero-current potentiometry.

Thermomechanical properties of composite films of polyacrylonitrile with chitin and chitosan

Composite films were prepared from polyacrylonitrile synthesized by anionic and radical polymerization and combined with chitin or chitisan. The thermomechanical properties of the films were examined. The compatibility of polyacrylonitrile synthesized by radical polymerization with chitosan was studied by DSC over a wide temperature range 140–280°C.

Fullerene C60 Aggregates in Polymethyl Methacrylate Films

The structure of aggregates of fullerene C60 introduced into films of radical polymethyl methacrylate in the stage of solution preparation was studied by wide-angle X-ray diffraction.

Cyclization and carbonization of anionic polyacrylonitrile in the presence of carbon nanofibers

Composites based on anionic polyacrylonitrile and carbon nanofibers were studied by X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, and electron microscopy. The effect of carbon nanofibers on the specific features of cyclization and carbonization of anionic polyacrylonitrile at temperatures of to 550°C was studied.

Mechanism of low-temperature carbonization of polyacrylonitrile

Low-temperature carbonization of polyacrylonitrile was studied in relation to the synthesis procedure, heat treatment conditions, and presence of natural polymers as cocarbonization participants.