T. I. Shevchenko’s research while affiliated with Lomonosov Moscow State University and other places

1. When silicas are modified with amines, not all surface silanol groups participate in the chemical reaction. 2. When amine-modified silica gels are heated, water is produced; the maximum rate of the formation of gas occurs at 625 and 750 K. Destruction of the modifying layer begins with the liberation of ammonia at T > 640 K. 3. Adsorption of SO2 and CO2 on aminated silicas is determined by the surface concentration of amino groups, by their nature, and by their mutual position.

1. A superthin multilayer fiber, Sivol, has significantly more developed porosity in comparison to the starting material, chrysotile asbestos. The values of S and the pore volume of Sivol are one order of magnitude higher than for chrysotile asbestos. 2. In contrast to Silokhrom, the adsorption values of CH3OH and H2O for Sivol and the silica fiber and the values of S calculated from the adsorption isotherms of these substances are significantly higher than the values measured with cyclo-C6H12 and krypton due to the specific interaction of the molecules of CH3OH and H2O with the surface of the adsorbents and the presence of fine pores in them.

The pore structure of modified polymeric sorbents based on copolymers of styrene with divinylbenzene and 2,3-epoxypropyl methacrylate with ethylene dimethacrylate was studied. The study was conducted by methods of thermal desorption of nitrogen, analysis of the adsorption-desorption isotherms of perfluorooctane vapor, absorption of liquid cyclohexane, and mercury porosimetry. The applicability of these methods to the study of the structure of porous polymers was analyzed.

The adsorption capacity of porous polymers, particularly macroporous anionites, depends on the polymer geometric structure and surface chemistry. This review discusses the effect of the conditions of synthesis, the nature and content of the crosslinking and the porogenic agents on the geometric structure of porous polymers and their adsorption capacity with regard to certain gases (CO2, H2S, SO2, NO2, SiF4). The adsorption capacity increases with the number of active functional groups in the polymer (provided they are accessible to the adsorbate molecules). Heats of gas adsorption by polymers containing different functional groups are reported and the mechanism of adsorption is discussed. It is shown that adsorption of chemically active gases may involve formation of weak chemical bonds between the gas molecules and the corresponding functional groups of the polymer. Adsorption of gases as affected by that of water and pre-moistening of porous polymers is considered.

The macroporous co-polymer of 2,3-epoxypropyl methacrylate with ethylene dimethacrylate was modified by using amines containing primary, secondary and tertiary amino groups. Fe3+, Co3+, Co2+ and Ni2+ salts were equilibrium sorbed on the co-polymer modified with diethylenetriamine. An investigation of the sorption and desorption of acidic gases (sulphur and carbon dioxides) on these polymers containing hydroxyl and amino groups showed that both the sorption and desorption capacity towards these acidic gases can be regulated. Co-polymers subsequently modified with cations readily sorbed not only sulphur dioxide, but also ammonia.