I. Ya. Polyakova

Proton-conducting sorption-active cyclam-based layers on chemically modified PVC surfaces of cellulose fabric

At different concentrations of hydrochloric, sulfuric, and phosphoric acids, the conductivity of the following electrochemical cell was measured: anode-acid solution-in-air bridge-acid solution-cathode. Cellulose fabric, the fibers of which are encapsulated in polyvinyl chloride, the surface of which is chemically modified with porous layers of aggregates formed by acid molecules and salt groups of ethanol and acetate cyclams, served as the bridge. The range where the logarithmic conductivity is proportional to the acid concentration is found. In this range, the molar contents of acids and water in the layers are estimated, the presence of aggregates composed of acid hydrates and cyclam salt groups is determined, the structure of layer is studied, and the similarity between the H+ conductivity of the layers on fabric and the conductivity of membranes based on polymers involving the skeleton ammonia salt groups is followed. For the aggregate layers, the specific surface; the limiting volume of pores; and the adsorption capacities for water, alcohol, benzene, and hexane vapors are measured. The formation of aggregates is shown to produce an insubstantial effect on the adsorption characteristics of the surface. During migration of H+ ions in the fabric and on its surface, the following process was carried out in the electrochemical cell: adsorption of NH3, formation of NH4+ ions, and transfer of NH4+ ions to the catholyte. The migration velocity of H+ ions is shown to correspond to the measured current in the circuit, and NH4+ ions formed are found to be accumulated in the catholyte.

PVC materials with sorption-active surface of ethanol cyclam nanofilms

Materials with sorption-active nanofilms based on PVC materials with surface layers modified into ethanol cyclam nanofilms were obtained, based on which new functional materials with given properties can be developed. The properties and molecular structure of ethanol cyclam nanofilms with different sorption-active surfaces were studied using physicochemical research methods.

Synthesis and proton conductivity of adsorption-saturated and solvated porous hydroxyethylated cyclam layers on the surface of PVC-coated cellulose fabric

Porous layers of associates of adsorption-saturated and benzene- and hexane-solvated chloride and sulfate of hydroxyethylated cyclams with acid aqua complexes were synthesized on the surface of PVC-coated cellulose fabric. The porous structure of the layers includes a system of internal pores connected with the external pores via the diamine rings of the common walls of the hydroxyethylated cyclam nets; the internal pores are filled with the associates; the solvent molecules are adsorbed on the developed surface of the layers or solvate it. The H+ motion rate in a layer placed in solvent vapors or liquid solvents was measured; the layers were found to be nonlinear H+ conductors. The potential of H+ transition from the acid solution into the layer, the H+ mobility constant, and the field variation constant of the H+ mobility of the layer depend on the layer composition. The adsorption and solvation are accompanied by the formation of host-guest molecular complexes between the diamine rings of the cyclam nets and the benzene or hexane molecules, affecting the resistance of the associates to the incorporation of H+ ions and the H+ mobility in the associates.

Production of materials with sorption-active cyclam layer on polyvinyl chloride surface encapsulating cellulose matrix fibers

Materials with multifunctional sorption-active surfaces are produced based on polyvinyl chloride covering a cellulose matrix and yield an active cyclam layer. Factors that determine the chemical stability and the sorptivity of the material are determined. Conditions of the production and properties of the materials are studied using various physicochemical methods.

Cellulose fabric covered with a PVC coating filled with active carbon and a porous semiconductor layer with conductivity depending on adsorption coverage and solvation

A multilayer system that involves cellulose fabric covered with a PVC coating filled with active carbon and a porous layer composed of ethanol cyclams was synthesized and shown to be a high-resistance semiconductor due to the conductive properties of the part that consists of cyclams and active carbon. The effect of the inclusion of active carbon particles in the PVC coating and in the cyclam layer on the composition and structure of the whole system is discovered, and characteristics of the layer are determined. Systems that involve layers saturated with adsorbed vapors of ethanol, benzene, or hexane and those that involve layers solvated by the corresponding liquid solvents are synthesized. Adsorption and solvation are found to increase the electronic conduction of the layers. The specific resistance is shown to increase in a hexane < benzene < ethanol series, which correlates well with the increase in the number of solvent molecules per monomeric unit of the macromolecular ethanol cyclam network in the adsorption-saturated and solvated layers.

Synthesis and sorption properties of porous layers of cyclames on a modified polyvinyl chloride surface

The structure and adsorption properties of the porous layers of synthesized ethanol-cyclames and sodium acetate cyclames on a surface of polyvinyl chloride (PVC) encapsulating fibers of the asbestos tissue of chrysotile asbestos are studied. It is established that PVC is linked to the silicon-oxygen chains of magnesium hydrosilicate; the capsule ensures the stability of the asbestos tissue under the action of the concentrated solutions of acids and alkalis; its exterior reproduces the fiber surface and has a typical microrelief; and there are voids in the layers. We conclude that the specific surface of layers and the volume of the adsorption space are larger than those of the initial fibers, and the statistical capacity upon the adsorption of water vapor and polar and nonpolar organic molecules depends on the nature and affinity for cyclames.

Ion-conducting porous layers of sodium hydroxide complexes with hydroxyethylated cyclams on modified surfaces of a PVC coating for fabrics

Layers of polynuclear NaOH complexes with aza-crown groups are synthesized using a NaOH solution on porous layers with internal voids of macromolecular hydroxyethylated cyclams on a chemically modified PVC coating that encapsulates the fibers of a cellulose fabric. The porous structure of the layers is studied along with the adsorption of solvent vapors (benzene, hexane) and liquid solvents. The OH− conductivity of layers that act as electrochemical bridges is examined in air and the vapor and liquid phases of the solvent. It is established that the complexes occupy the voids and have a developed system of hydrogen bonds. The pores are filled during adsorption. Molecules of the solvent are connected by the macrocyclic groups of pore walls into a host-guest complex as the structural system of hydrogen bonds changes. It is observed that the motions of OH− ions start at a certain value of potential Eover. An expression describing the dependence of velocity of voltage is obtained: v′ = K1(E − Eover) + K2(E − Eover)2, where K1 is the conductivity constant of a layer and K2 is the constant of transfer acceleration, determined by the structural changes in the layer in a field of moving OH− ions. It is shown that the values of Eover, K1, and K2 depend on the composition of the complex and the nature of solvents.

Electrically conductive PVC layers filled with active carbon containing H+-conducting porous structures of sulfuric acid complexes of cyclams on fabrics

Electrically conductive PVC layers are synthesized. The layers are filled with active carbons containing porous H+-conductive structures of hydroxyethylcyclam/sulfuric acid complexes crosslinked with cellulose fabric. They are interlaid with layers based on the same structures containing added benzene and hexane adsorbates and solvates. It is found that upon anode or cathode polarization of the layers as H+-conductive electrochemical bridges in air and in the vapor and liquid phases of benzene and hexane, either the electroreduction of H+ to H2 or the electrooxidation of H2O to O2 occurs in the areas of contact between active carbon particles and the complexes. The dependences of rates of H2 and O2 formation on the voltage are studied. The magnitudes of overvoltage and the constants of electrochemical reactions are found to depend on the composition of a layer.

Sorption-active nanofilms of polynuclear Ni(2+) and Ni(0) ethanol-cyclam complexes on the surface of polyvinyl chloride coating on cotton

The interaction between Ni(2+) ammonia chloride complexes and ethanol-cyclam groups of the sorption-active surface nanofilm on a PVC coating applied to cotton is studied. Novel materials with a nanofilm of Ni(2+) and Ni(0) ethanol-cyclam chloride are obtained. Molecular structure and properties of the cyclam nanofilms produced are studied using physicochemical methods.

Materials based on carbon-filled porous layers of PVC cyclam derivatives cross-linked with the surfaces of asbestos fabric fibers

The synthesis of bilayer materials with porous upper layers composed of PVC hydroxyethylcyclam derivatives filled with carbon and a layer consisting of hydroxyethylcyclam, cross-linked via Si–O–C groups with the silica chains of a developed surface of asbestos fabric, is described. The aza-crown groups in these materials are bound with aqua complexes of H2SO4 or NaOH. The structure of the materials is examined, their adsorption characteristics are determined, and the rate of motion of H+ or OH– ions in electrochemical bridges is measured, while the formation of H2 and O2 in their cathodic and anodic polarization is determined as a function of voltage. It is shown that the upper layer of these materials is adsorption-active and electronand H+- or OH–- conductive, while the bottom layer is only H+- or OH–- conductive; through it, the upper layer is supplied with the H+ or OH– ions needed for the regeneration of the aqua complexes broken down to H2 and O2 on carbon particles.