L. B. Gulina

Reaction of gaseous hydrogen fluoride with the surface of lanthanum chloride solution to form LaF3·nH2O film and microtubes thereof

We present the first study of the reaction of hydrogen fluoride fed from the air side of the air/LaCl3 aqueous solution interface with lanthanum cations. The reaction yields a 0.5–1.5-μm LaF3·nH2O surface film with hexagonal crystal structure, built of the ordered planar LaF3·nH2O nanocrystals (the crystal thickness of 7–15 nm and surface area of 0.5–2.5 μm2). The nanocrystals are oriented perpendicular to the interphase boundary, and their packing gets looser towards the solution side of the film. Upon drying in air, the LaF3·nH2O film rolls up to form microtubes 20–100 μm in diameter and up to 2 mm long. The microtubes are likely formed due to the contraction forces developing upon drying in the lower, loosest part of the wet film.

Ozone interaction with manganese acetate solution. Formation of HxMnO2·nH2O layers and microtubes based on them

We present the first study of Mn(II) cations interaction with ozone fed onto the air/aqueous manganese acetate solution boundary. In the reaction, the layer of HxMnO2·nH2O of birnessite structure has been formed at the surface. Subsequent ∼1–3 μm thick layers drying at air has led to their rolling up to form microtubes with diameter of 20–50 μm and up to 10 mm long.

Catalytically Active Filters Deposited by SILD Method for Inhibiting Sensitivity to Ozone of SnO2-Based Conductometric Gas Sensors

Research has shown that successive ionic layer deposition (SILD) technology can be used for improvement operating characteristics of solid state conductometric gas sensors. This technology gives possibility to deposit nanolayers of noble metals such as Pd, Ag, SnO2-Au nanocomposites, and oxides of transition metals such as Cu, Fe, Mn, Co, which can play the role of catalytically active filters for ozone.

The interaction of gaseous SiF4 and HF with surface of aqueous solution of LaCl3 leading to the formation of the LaF3–SiO2·nH2O nanocomposite and microtubes on its basis

The interaction of gaseous SiF4 and HF with lanthanum cations at the surface of aqueous solution of LaCl3 has been studied for the first time. The reaction results in the formation of about 600 nm layer of a hydrophobic substance at the solution surface. According to the data of electron microscopy, IR Fourier spectroscopy, X-ray diffraction, and X-ray spectral microanalysis, the layer is formed by the LaF3‒SiO2·nH2O nanocomposite and consists of 2D LaF3 nanocrystals and SiO2 spherical nanoparticles. Drying in air at room temperature is accompanied by the layer rolling with the formation of microtubes (20 μm in diameter and up to 300 μm long).

Silver nanoribbons synthesized on a silicon surface by the “layer-by-layer” technique

Conditions for the synthesis of silver nanoribbons on a silicon surface by the “layer-by-layer” technique were determined for the first time. The synthesized structures were studied by scanning electron microscopy, energy-dispersion microanalysis, and X-ray diffraction. A conclusion on the sequence of possible reactions occurring on the surface during the synthesis was drawn on the basis of the experimental data.

Agx-SnO2 nanocomposite layers synthesized by ionic layer deposition onto silica surface

Possibility of performing synthesis of Agx-SnO2 nanocomposite layers on the silica surface by ionic layer deposition was analyzed, and the factors affecting the layer morphology and composition were determined. The synthesized layers were examined by visible transmission spectroscopy, as well as by scanning electron microscopy, IR Fourier-transform spectroscopy, and X-ray spectral microanalysis.

Synthesis and study of cerium(IV) polytungstate nanolayers

For the first time the conditions for the synthesis of cerium(IV) polytungstate nanolayers on the silicon surface by the method of ion layering were defined. The layers were studied by scanning electron microscopy, X-ray microanalysis and transmission FT-IR spectroscopy. The synthetized layer is shown to have a globular structure with the size of the globules in the range of 30–50 nm, with the ratio of cerium/tungsten atomic concentrations equal to 0.8.

Layers of nanocomposite FeOOH-xH3PW12O40 synthesized by ion-colloid layering

For the fi rst time the conditions of synthesis by ion-colloid layering of layers of nanocomposite FeOOH—xH3PW12O40 on the surface of silica were defined using successively adagulation of FeOOH colloidal particles, and adsorption of H3PW12O40. Investigation of the synthesized layers was carried out by scanning electron microscopy, X-ray microanalysis, UV and Fourier transmitting infrared spectroscopy.

Synthesis of the nanocomposite SnO2-Aux0 -(H3PW12O40)y·nH2O layers on the silica surface by the layer-by-layer method

Conditions for the synthesis of the SnO2-Aux0-(H3PW12O40)y·nH2O nanocomposite layers by the method of ionic epitaxy were determined for the first time. The layers we investigated by the method of scanning electron microscopy, energy dispersion microanalysis, UV and IR Fourier transmission spectroscopy. On the basis of the experimental data conclusions were drawn on the composition and structure of the synthesized layers.

Layers of xCuS-SiO2·nH2O nanocomposite, synthesized by the layer-by-layer technique

For the first time conditions were determined for the synthesis of CuxSiO2+x·nH2O nanostructured layers by consecutive adsorption of copper ammine cations and adagulation of colloidal SiO2 particles and also for the synthesis of xCuS-SiO2·nH2O nanocomposite layers by consecutive surface adsorption of copper cations and HS− anions. These layers were studied by means of UV and visible transmission spectroscopy, X-ray spectral microanalysis, and scanning electron microscopy. Schemes of the surface reactions were constructed on the basis of this experimental material.