A. V. Dorokhov

On the nature of the phase “η-TiO2”

Conditions for a sulfate method for the synthesis of a metastable modification, which has been previously described as “η-TiO2” (Dadachov, 2006), were found and the stability region of this phase in the hydrolysis temperature–hydrolysis duration coordinates was determined. Investigation by a number of methods (X-ray powder diffraction, a differential dissolution method, thermogravimetry, IR spectroscopy, Raman spectroscopy) showed that the η-phase is not a polymorph of TiO2 but is a pseudo-polymorph of titanium dioxide hydrate. It was demonstrated that nanoparticles of the low-temperature η-phase consist of the [TiO2−x·mH2O] core, the structure of which can be described as a superstructure in relation to anatase, and an amorphous shell containing TiO2−x (trace amount), OH, HSO4 and water. The average crystallite size depends on the ratio of the constituents.

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.

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.

Zn complex with N-(4′-Benzo-15-crown-5)-2-(amino-N-tosyl)-phenylaldimine: Synthesis, crystal structure, and vibration spectrum

The ZnL2 complex (I) (HL = N-(4′-benzo-15-crown-5)-2-(amino-N-tosyl)phenylaldimine) is synthesized and studied by IR spectroscopy and X-ray diffraction analysis. The crystals are monoclinic: a = 23.139(2) Å, b = 19.931(2) Å, c = 14.604(2) Å, β = 121.20(1)°, Z = 4, space group C2/c, R = 0.751 for 766 reflections with I > 2σ(I). The Zn atom in a molecule of the complex lies on a twofold axis and is coordinated at the vertices of a distorted tetrahedron by four N atoms of two HL ligands (average Zn-N distance 2.024 Å).

Synthesis and ion-selective properties of 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy)ethoxy]cyclohexane (L) and its structural analogs. Crystal structure of L

Potentially hexadentate phosphoryl podands 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy) ethoxy]cyclohexane (L), 1,2-bis[2-((2-diphenylphosphoryl)phenoxy)ethoxy]cyclohexane (L1), and 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy)ethoxy]benzene (L2) are synthesized. Stability constants of complexes formed by L, L1, and L2 with alkali-metal 2,4-dinitrophenolates in mixed THF—CHCl3 solutions (4: 1 by volume) are determined. Electroanalytical characteristics of ion-selective electrodes with hexadentate phosphoryl podands having different structures used as active components of their plasticized membranes are compared for cations of alkali and alkaline-earth metals. The IR spectra are described. The crystal structure of L is studied by X-ray diffraction.

Composites Based on Polystyrene Microspheres with Nano-Scaled Titanium Dioxide

This study produced for the first time composites based on polystyrene microspheres with nano-sized titania synthesized by sulfate and sol-gel methods, as well as commercial Hombifine N, Hombikat UV100, and Degussa P25. The starting samples and the composites were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption capacity, and IR spectroscopy. The highest content of nano-titanium dioxide both in the bulk and on the surface of microspheres was obtained with the use of Hombikat UV100. This sample has the largest specific surface area and a high content of reactive OH groups. The adsorption properties of composites were investigated.

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.

Synthesis, crystal structure, and vibrational spectrum of lithium N-(4′-benzo-15-crown-5)-5-bromo-2-hydroxyphenylaldiminatozinc perchlorate dihydrate

The synthesis, the IR absorption spectrum, and X-ray diffraction analysis of the complex [ZnLi(L1)2(H2O)](ClO4) · H2O (I) (HL1 = N-(4′-benzo-15-crown-5)-5-bromo-2-hydroxyphenylaldimine) are described. The crystals of I are monoclinic, a = 19.840(4) Å, b = 13.947(3) Å, c = 19.956(4) Å, β = 117.06(3)°, V = 4917.4(17) Å3, Z = 4, space group P21/n, R = 0.0609 for 1409 reflections with I > 2σ(I). In the complex cation [ZnLi(L1)2(H2O)]+, the Zn atom is bound to a distorted tetrahedral array of two N atoms (av. Zn-N, 2.027(10) Å) and two O atoms (av. Zn-O, 1.8968(8) Å) of two deprotonated L1 ligands. The Li atom linked to the five ether oxygen atoms (av. Li-Oether, 2.254(3) Å) sits atop the benzo-15-crown-5 (B15C5) macrocyclic plane of one coordinated L1 ligand. The Li coordination is completed by water oxygen (Li-O(w1), 1.83(5) Å). The B15C5 cavity of the second coordinated ligand L1 is vacant.

Conversion of the surface layers of poly(vinyl chloride) into aminoethyl podand nanofilms as a matrix at the surface of borane-selective sorbents

Nondetachable nanofilms of aminoethyl podands were obtained at the developed surface of PVC materials. Interactions of these films with gaseous boranes were studied for use as a hydrogen source. The steps of surface development were checked and the nature of diborane absorption was studied by FTIR spectroscopy.